LS1_Edit is for use with 1997 to 2002 Model years. This document provides you with information about LS1_Edit software for 1997-2000 cars with the LS1, or LS6 engine, and 1999-2002 trucks with 4.8, 5.3, or 6.0L engines.

The purpose of this document is to provide you with adequate information to change PCM parameters correctly. We encourage you to read this guide before you begin in order to avoid doing something careless later on. The developers of LS1_Edit are not responsible for any errors made by the user of this editor.

This document will cover common configuration parameters required when tuning both stock and modified drivetrains.

This is not a document on how to tune, only on how to use the editor.

1.1 System Requirements

LS1_Edit runs on a Windows platform with a minimum Pentium 133 with 48 MB RAM or better. The software, including all DLL files, requires approximately 15MB of disk space.

A RS232 serial port with a DB9 connector is required for communications. Parallel and/or USB ports are not supported.

1.2 Warnings and Operator Responsibilities

LS1_Edit is a complex and powerful tool that allows you to completely modify the computer that controls your engine and transmission. As a result, causing significant damage to your engine, transmission, car, and car's computer is also a possibility.

It is possible for a user to tell the engine and/or transmission to behave dangerously (e.g. shift into first at 80 MPH, disable the knock retard and cause engine damage from pinging, or to simply make the PCM non-functional). Because these risks are significant and easily avoidable, the following sections will discuss the warnings and suggested guidelines associated with operating LS1_Edit. Please read the following sections before using the editor.

1.2.1 Warnings

1. Developers of these tools (hardware and software) make neither claims nor warrantees.

2. Users are solely responsible for use these tools, and all results from using these tools.

3. The developers of LS1_Edit are not responsible for any errors made by the user of this editor.

4. You can destroy your PCM by:

· Losing battery power in the car while programming (do not leave a charger attached while programming, and do not attempt any other work around the battery)

· Losing power to your computer or laptop while programming

· Losing the cable connection while programming

· Having a virus checker stop the programmer on your computer Note: It is important that you disable any virus checkers prior to programming.

· Having a screen saver stop the programmer Note: It is important that you disable screensavers prior to programming.

· Having a software defect stop the programmer

· Having a hardware fault stop the programmer

· Trying to start the car while programming

· Having another application run on your computer that stops the programmer

5. Incorrectly changing variables in the PCM can damage the engine and the transmission.

1.2.2 Important Usage Guidelines

Because LS1_Edit has the capability to completely reprogram your PCM, we strongly suggest that you adhere to these few simple guidelines

We strongly urge that you:

1. Make a backup of your PCM's original memory file, and put it away in a secure area (e.g. a directory that you'll seldom use, or a floppy disk in a safe place). Note: You cannot damage your PCM when you read it.

2. Back up your PCM file.

3. Do several reads before you actually write to your PCM for the first time.

4. Do a read prior to a re-program to re-confirm that your setup is correct. (This ensures a reliable connection.)

2 Getting Started

This section will provide you with information about installing, launching and editing LS1_Edit files.

2.1 Installing LS1_Edit on Your PC

To install LS1_Edit on your PC, follow the instructions that you received by email along with the software at the time of purchase.

2.2 Launching LS1_Edit

To launch LS1_Edit, go to the Programs on your Start Menu and select Tune It Up. From the Tune It Up Menu, select LS1_Edit.

The opening screen should appear as in Figure 1: LS1_Edit Opening Screen.

Figure 1: LS1_Edit Opening Screen

2.3 Opening a File

When starting the editor, go to the “File” menu and select “Open”. The editor assumes you have a *.LS1 file for your PCM. This file contains a Flash image from the PCM. LS1prog reads and writes the flash using this format. Before you start editing a file make sure you have backed up an original copy of your *.LS1 file. If you make changes to the file that doesn’t work well in your car, you always want to have the original file for a safety backup.

To open an existing file, select Open from the Edit Menu as shown in Figure 2.

Figure 2: Selecting "Open" from the File Menu

Select the appropriate file from the Open window as shown in Figure 3.

Figure 3: Selecting a File to Open

Click “Open” and the file should open in the editor window similar to the file shown in Figure 4.

Figure 4: Opening New File

Main Window

Notepad

Prom Type Window

You will see three windows on the opening screen: the main window, the Prom Type window and the Notepad window.

2.3.1 Main Window

The main window displays identifies the calibration within your vehicle, file name, broadcast code of the PCM flash, etc.

2.3.2 Prom Type Window

The year, engine and car type will be identified in the Prom Type Window.

2.3.3 Zero VIN

This is a customer requested feature to Zero the last 3 digits of the VIN

2.3.4 Notepad

The Notepad is a 256-character scratch pad. Whatever you write on this notepad will be save in the Flash binary. Use it for your tuning notes, and it will always be with the chip.

2.3.5 Error Messages

If the editor cannot read a file, you will see one of the following error messages:

“This is an Unknown PCM.”
This error occurs when the editor encounters a file that it doesn’t recognize.

“This is not a supported PCM.”
This error occurs when the editor cannot reconcile the year and make of the vehicle provided.

“I have not tested this file type. Please send me a copy.”
This error will occur when the editor encounters an unknown build. It has identified the year and engine type. This should be a supported PCM, but was from a software build that I have not seen yet. Tables move with each build. You need to send me a copy of this file, so I can figure out what the table locations are.

2.4 Editing a File

To edit a file, select one of the following sections from the Edit Menu:

· Transmission Calibration (Chapter 3)

· Engine Calibration (Chapter 4)

· System Calibration (Chapter 5)

· Speedometer (Chapter 6)

· Engine Diagnostic (Chapter 7)

See the appropriate chapter for more information about each section.

2.5 Editing Tables

Once you have selected an area to edit, you will see a window with three tabs at the top of the window: Table Edit, Graph View, and Select Rows.

2.5.1 Table Edit

If you point to any cell in the table and click the left mouse button, the selected cell will have a gray background, and the cell content will be displayed in the text window in the upper left of the display window. This display works like the old excel spreadsheet format.

All changes must be made in this single text window on the upper left of the Table edit display. To transfer this new data to the highlighted cell, just point the mouse to a new cell and click the left mouse button. All changed cells will show a blue background. You can edit any number of cells. Since the change takes place when you leave the cell, make sure you leave the last cell you made changes in, by clicking on a new cell.

If you don’t like your changes click the “clear changes” button to go back to the original data. When you are satisfied with the new table you can commit it by clicking on the “Apply Changes” button.

NOTE: When you enter a value and move to the next cell, you may find that the saved value has changed from what you originally entered. The editor allows you to enter a value in scaled units. When the data is saved, it must be quantized into the nearest single byte or integer value. The value shown after saving is the closest value in the PCM’s internal format to the number you entered.

2.5.1.1 Edit Whole Table Frame

You can edit all cells that are visible on the graph at once. The Frame “Edit Whole Table” will apply these changes to all the Visible graphs. You have 3 choices in this Frame:

Add a value. The value you enter in the value window is added to all cells. Note a negative number in the cell will subtract the value from all cells.

Fill value. All cells will be set to the value in the Window.

Multiply by %. Entering 100 will result in no change. Enter 50 and all cells will be cut in half. Enter 150 and all cells will be 1.5 times the current value.

There is one other option in the Edit whole table Frame. If the “Use selected cells only” checkbox is selected, all changes apply only to the highlighted items. The Highlighted items can be selected by pointing to a cell, holding down the left mouse button, and dragging across an area. Any rectangular area in the table can be selected , but random single cells cannot be selected.

2.5.1.2 Compare File Frame

You can open a second file and compare or copy tables from it. In order to use these features, you must use the Read File button in the Compare file frame to read in the second file. The file name of the second file will now appear on the second radio button

If you select the top radio button, you will be viewing the data in the original file.

If you select the second radio button, you will be viewing the data in the compare file.

If you select the third radio button – Difference you will be looking at the difference in the two files, on a cell by cell basis.

While Viewing the original file, If you click on the Copy File button, It will copy the data in the visible, part of this table from the compare file to the original file. The Use Selected cells option also works for this feature.

Figure 5: Transmission Calibration Table Edit Screen

2.5.2 Graph View

Graph View presents the information available in the Table Edit in a graph form. Information is not editable in this view. To change variables, you must return to Table Edit view. However, you may change the appearance of the graph by choosing either a
2- or 3-dimensional graph display using the radio buttons at the bottom of the Tab.

Figure 6: Transmission Calibration Graph View

Note: If you hold down the CTRL key after selecting only the 3D Graph radio button at the bottom of the graph, you can change the angle and viewpoint by rotating the graph with your mouse.

2.5.3 Select Rows

The selected rows tab simply displays the rows that appear in the Table Edit view. Compare Figure 7 below with Figure 5 as an example of the relationship of the Selected Rows view with the Table Edit view. If you uncheck a row, it will no longer be included in the displayed Table, or graph, and will not be edited in the edit whole table Frame. The data will remain in the file, but be unchanged.

Figure 7: Transmission Calibration Selected Rows

2.6 Saving a File

Saving edited files to a new file name each time is recommended. Remember to keep an original version of your file for safety. To save a file, choose Save As from the File Menu.

2.7 Uninstalling LS1_Edit

To uninstall LS1_Edit from your computer, go to the Control Panel, select “Add/Remove Programs” and remove “Tune It Up” from the menu.

3 Transmission Calibration

To edit the Transmission Calibration file, select “Trans Calibration” from the Edit menu as shown in Figure 8.

Figure 8: Selecting from the Edit Menu

A second window will open and the Transmission Calibration Main Menu will display. This window allows you to access tables associated with Shift Speed, Shift Firmness, TCC, and the M6 Skip Shift parameters.

3.1 Shift Speed Tab

The Shift Speed Tab is dedicated to the speed at which the transmission shifts.

Within the Shift Speed Tab, you may edit the WOT Shift MPH, the Hot Shift MPH, or one of two tables: Normal Shift Speed and Performance Shift Speed.

Figure 9: Transmission Calibration Shift Speed Tab

The PCM supports two modes of operation – normal mode, and performance mode. Some car models have a dash-mounted switch that enables the operator to alternate between modes. Performance mode usually has a more aggressive shift speed and firmness (e.g. the shift RPM is higher, and the shift is tighter).

3.1.1 Shift Speed

This table controls the Part throttle shift speed. The entries are in MPH. There is a separate curve for each upshift, and each downshift. The curve is shift MPH vs Throttle position.

3.1.2 WOT Shift Speed

These are the shift MPH at Wide Open Throttle

3.1.3 Hot Shift Speed

These are the shift Speeds used in WOT mode when the Transmission is Hot.

3.1.4 Performance Shift Speed

These are the shift MPH at Wide Open Throttle when in Performance Mode

3.1.5 WOT Shift RPM

This is the Shift RPM when at WOT in Normal Mode. Both the MPH and RPM thresholds must be met to start a shift.

3.1.6 Hot Shift RPM

This is the Shift RPM when at when the transmission is hot. Both the MPH and RPM thresholds must be met to start a shift.

3.1.7 Performance Shift RPM

This is the Shift RPM when at WOT in Performance Mode. Both the MPH and RPM thresholds must be met to start a shift..

3.2 Shift Firmness Tab

The Shift Firmness Tab deals with how the transmission Shifts .

Figure 10: Shift Firmness Tab

3.2.1 Positive Pressure vs. Temp

This table, although not entirely intuitive, is the way to adjust shift firmness. It consists of 17 curves. Each one of the curves represents a different Temperature. The curve illustrates the force motor current versus throttle position.

The force motor is the line pressure control solenoid in the transmission. It puts out maximum line pressure when you send it zero current. The force motor puts out the Minimum line pressure at 1.2 amps input current.

So the lower the input current, the harder it will shift. You will probably only want to adjust the curves in the normal operating range, making them firmer at higher throttle positions. Here is a simple example of how to firm up the shifts on a 99 Camaro.

1) Select Edit > Transmission Calibration > Shift Firmness Tab > Positive Pressure vs Temp

2) You usually don't want to Firm up shifts when the Trans is cold, so Uncheck from -40 Degrees to 20 Degrees

3) We don't want to make much change in low TPS, around town driving,

but want to make a lot of change at 100% TPS.

4) Here is a tricky way to edit the whole table. Go to the "edit

whole table" Frame. Set the value to 110.

5) Push Mult % This raises all the values by a percentage - which may

seem very strange, because raising values will soften the shift.

6) hit Apply Changes

7) Now we firm it up, change the number in value to -108

8) Push Add Value

9) hit Apply changes

10) Select the check box for the low temps again, so all boxes are

checked.

11) Now look at all the curves together, you will see that I made no

change at 0% TPS, and a significant change at 100% TPS.

The result is that the more you depress the throttle, the higher the line pressure gets. This will leave you with reasonable shifts in around town driving, but stiffen up as you get more aggressive.

3.2.2 Desired Shift Time

This Table sets the desire time to shift. If you set it to zero, it will accelerate transmission wear. You can reduce these values to quicken the shifts.

3.2.3 Abuse Mode

3.2.4 Upshift Torque Reduction

This table controls the torque reduction during a shift as a function of Engine Torque in Foot Lbs., and Gear

3.2.5 Base Pressure vs Torque

3.3 TCC Tab

The TCC Window deals with locking and unlocking the torque converter clutch.

Within the TCC tab you may select one of four tables:

· Normal Mode MPH vs. %TPS

· Normal Mode Max vs. %TPS Release

· Performance MPH vs. %TPS

· Performance Max vs. %TPS Release

The PCM supports three modes of operation – normal mode performance mode, and cruise mode. Some car models have a dash-mounted switch that enables the operator to alternate between modes. Performance mode usually has a more aggressive shift speed and firmness (e.g. the shift RPM is higher, and the shift is tighter). Cruise mode is used when the Cruise control is set. In each mode you have two tables; MPH vs. %TPS and Max vs. %TPS

Figure 11: Transmission Calibration TCC Tab

3.3.1 MPH vs. %TPS

This table allows you to set the MPH at which the TCC (Torque Converter Clutch) Locks and unlocks as a function of the current gear, and the Throttle position.

3.3.2 Max vs. %TPS Release

This is the Maximum Throttle before the TCC releases, as a function of the current gear, and the Throttle position.

3.3.3 TCC MPH thresholds

These thresholds apply when at WOT (Wide Open Throttle).

3.3.4 Allow TCC lock during Shift

This is a Boolean to allow the TCC to stay locked.

3.4 M6 CAGS/Skip Shift

M6 CAGS (Computer Aided Gear Selection) is also known as “Skip Shift” and forces the operator to shift from 1^st to 4^th gear.

Figure 12: Manual Trans Computer aided Gear selection

4 Engine Calibration

4.1 Ignition Tab

The Ignition Tab is dedicated to controlling spark advance.

Within the Ignition Tab you may select one of the following tables:

· High Octane Spark Advance vs. RPM and Load

· Low Octane Spark Advance vs. RPM and Load

· Base Spark In Drive

· Base Spark in Park

· Spark Retard Limit

· Knock Retard

· Torque Management

Figure 13: Engine Calibration Ignition Tab

4.1.1 Spark Advance vs. RPM and Load

When the PCM sees excessive Knock, It assumes you are using poor gas, and shifts to the Low Octane Spark Advance table.

The Spark advance Table, indicates the ignition advance the PCM applies for the conditions in that cell. The horizontal Axis is engine RPM, the vertical axis is load. The load is measured as Grams per Cylinder. This is a measure of the air flow into each cylinder.

4.1.2 Base Spark

Base spark is the spark advance applied when the throttle is closed. The axis are the same as the Spark Advance table, but the RPM scale ends at 4800 RPM.

4.1.3 Spark Retard Limit

This table limits the maximum spark retard.

4.1.4 IAT – MAP Timing Adjustment

This table is the adjustment to the timng advance as a function of Inlet Air Temperature and Manifold Pressure in Kpa.

4.1.5 Knock Retard Frame

4.1.5.1 Attack vs. RPM –

This Table gives the number of degrees added to the Knock retard for each Knock event it detects.

4.1.5.2 Decay vs. RPM

This table is the Percent Decay that is applied every 2 engine revolutions.

4.1.5.3 Attack Gain vs. Temp

This is a multiplier that adjusts the Knock attack for Temperature.

4.1.5.4 Attack gain vs. Altitude

This is a Multiplier to adjust the knock attack for altitude.

4.1.5.5 Maximum Knock Retard vs Load

This table show the maximum retard allowed for a given MAP reading

4.1.5.6 Maximum Knock Retard vs RPM

This Table is the maximum allowed retard as a function of RPM.

4.1.6 Knock Learn Gain Frame

This frame has the parameters that determine when the PCM goes into learn mode for Spark Knock.

4.1.6.1 Minimum MAP

This is the Minimum MAP reading to enable Knock retard Learn Gain

4.1.6.2 Maximum RPM

This is the Maximum RPM at which it can learn

4.1.6.3 Minimum RPM

This is the Minimum RPM at which it will learn Knock gain

4.1.6.4 Minimum Coolant Temp

This is the Minimum coolant temperature at which it will learn

4.1.6.5 Minimum Inlet Air Temp

This is a minimum Air Inlet Temperature at which it will learn

4.1.6.6 Total Retard

This is the maximum retard that it can generate

4.1.7 Torque Management Frame

4.1.7.1 TCS Retard vs RPM

There are 2 retard tables used by the traction control system, only one seems to be used in each application. The table shows the amount of timing retard for a given RPM.

4.1.7.2 Torque Reduction

This table defines the Timing retard used to implement the torque reduction that is requested in the shift table.. It defines the timing retard that is used for a requested % torque reduction. See the Transmission Page, Shift Firmness tabs for the Abuse control parameters.

4.1.7.3 Maximum Torque

This parameter is a maximum torque limit. It is in Foot Pounds.

4.1.7.4 Abuse Mode Test

This test is in the engine code. The test is only run when the transmission is in gear, and Engine RPM is above this threshold, and the Speed is below this threshold. So if you set the Speed = 0, and the RPM = 7000, The abuse test will only run when you are in gear with the engine RPM > 7000, and the Speed < 0 MPH. Which will disable this test.

4.2 Fuel Tab

The Fuel Tab is dedicated to controlling fuel air ratio or AFR.

Within the Fuel Tab, you may select the following tables:

Retard vs. RPM
2^nd Stage Retard vs. RPM
Torque Management
MAF
Injector Flow Rate
Volumetric Efficiency
Closed Loop Enable Temp
Fuel Pressure vs. Voltage
Injector Offset
Fuel Air Multiplier
Stoic Ration
Cylinder Size
Max Allowed Enrichment
Power Enrichment

Figure 14: Engine Calibration Fuel Tab

4.2.1 MAF

The MAF table is used to calibrate the Mass Airflow Sensor. You should only change this table if you have modified the MAF. The MAF will output a frequency that is proportional to the amount

of air flowing through the sensor.. This table assigns a Flow rate in Grams per second to each frequency step.

4.2.2 Injector Flow Rate

This table defines the size of the fuel injector. It should be modified only if you replace the Fuel injectors, or change the fuel pressure.

If you change the fuel pressure, you can calculate the new injector constant use this formula:

RatingNew = (sqrt (PressureNew/ PressureOld)) * RatingOld

The table shows the Fuel Flow rate in Grams per second, as a function of the intake manifold Vacuum in Kpa

4.2.3 Volumetric Efficiency

The volumetric efficiency table is critical when you have a MAF failure, and the PCM goes to Speed Density mode. It is not used in Normal WOT operation, but has an effect on closed loop fuel trim.

4.2.4 Closed Loop Enable Temp

This is the minimum temperature at which the PCM enters closed loop. Note, there are two temperatures in this table. The horizontal Label ( -40 C to 140 C) is the air temperature, The entry in the table is the coolant temperature that must be reached to enter closed loop.

4.2.5 Fuel Pressure vs. Voltage

This table is used to compensate for Voltage level effects on the fuel pressure. I would not change it unless I changed the fuel pump to an aftermarket unit. This is all 1, because the Fuel pressure regulator usually keeps the Fuel pressure at a constant level.

4.2.6 Injector Offset

The injector Offset Table is used to compensate for the time delay in opening the injector. This the base time used for every injector cycle. The calculated Pulse Width for the needed fuel is added to it. It is in Milliseconds.

4.2.7 Fuel Air Multiplier

The entry in this table is a multiplier. It is used to calculated fuel when there is a MAF failure, or when in Speed Density Mode.

4.2.8 Stoich Ratio

This should not be changed unless you change the type of Oxygen sensor.

4.2.9 Cylinder Size

This is really the displacement of one cylinder. It should be changed if you bore or stroke the engine.

4.2.10 Max Allowed Enrichment

4.2.11 Crank VE

This is the VE table used during Engine Cranking

4.2.12 Power Enrichment

This Frame contains the parameters affecting the Wide Open Throttle Power Enrichment

4.2.12.1 Temp

This table defines the Power Enrichment (additional fuel) that will be added at WOT vs. the coolant temperature when in PE mode

4.2.12.2 RPM

This table defines the Power Enrichment (additional fuel) that will be added at WOT vs. the current RPM. This is typically where fuel tuning for WOT operation is done. Values can be positive (Adding fuel) or negative (Subtracting fuel).

4.2.12.3 MAP to Enable

This is the Minimum MAP to enable Power Enrichment

4.2.12.4 MAP Hysteresis

The amount that the MAP must drop before disabling PE mode.

4.2.12.5 PE Delay

This is actually a delay used in some truck chassis. The PCM will count down, through this delay before entering Power Enrichment Mode. It should be 0 for any performance applications. It is not used in cars.

4.2.12.6 Wide Open Throttle

The parameters in this frame control when the PCM goes into WOT mode.

o Hot Temperature – When the Coolant Temperature is below this threshold the Cold WOT table is used. When The coolant Temperature is above this threshold, The Hot WOT table is used

o WOT Table – These Tables Control when WOT mode is entered. For each RPM step, the value is the Throttle position in % required to enter WOT.

4.3 Test Parameters Tab

The Test Parameters Tab allows you to fine tune GM diagnostic tests.

Within the Test Parameters Tab, you may edit the following functions:

· EGR Test Parameters

· Air Pump

Figure 15: Test Parameter Tab Window

4.3.1 EGR Test Parameters

This is the Speed in MPH required to enable the Egr when it is disabled, and disable it when it is enabled.

4.3.2 EGR Enable

This toggle will turn the EGR on and off

4.3.3 Air Pump

This is the temperature to disable the Air Pump.

4.3.4 Catalytic Converter OverTemp Enable

This toggle will turn the COT enrichment on and off

4.3.5 Catalytic Converter OverTemp Table

This table has the estimated Catalyst temperature to go into the 4 Cat cooling modes.

4.4 Limiters Tab

The Limiters Tab is dedicated to controlling the Rev Limiters, and the idle speed of the engine.

Within the Test Parameters Tab, you may edit the following functions:

· Idle Speed

· Limiters

· Rev Limit by Gear

· Rev Limiter by Temp

· Rev Limiter Delay

The Idle Speed Table allows you to enter information in RPMs. The first axis is in degrees Fahrenheit. The second axis is what gear you are in and whether the AC is on or not.

Figure 16: Limiters Tab Window

4.4.1 Idle Speed

The Idle speed table is the RPM at the given Coolant Temperature. There are 4 separate tables. One for in gear, and one for out of gear, and a second set used when the Air Conditioning is turned on.

4.4.2 IAC Park Position

4.4.3 Idle Air In gear

4.4.4 Throttle Follower

4.4.5 Limiters

The Limiters Tab provides a fuel cut off table by RPM. If RPM goes above this limit, it will cut the fuel off. The resume value is what the RPM must drop to to reenable the fuel.

4.4.5.1 Rev Limit by Gear

This table sets the rev limiter by the current transmission Gear

4.4.5.2 Rev Limit By Temp

This table sets the rev limiter based o the coolant temperature.

4.4.5.3 Rev Limit Delay

Is a time delay before switching from the Temp table to the Gear table. The delay is based on the Temperature at startup.

5 System Calibration

The System Calibration window allows you to change temperature at which the fan comes on to cool the engine.

Within the System Calibration Window, you may edit the following functions:

· Fan On Temp (First and Second Stage Fan)

· Vehicle Anti-Theft

Figure 17: System Calibration Window

5.1.1 First Stage Fan

This is the temperature in degrees F that the First stage fans come on. There are two setting.

5.1.2 Second Stage Fan

This is the Temperature in Degrees F, that the second stage Fans come on.

5.1.3 Vehicle Anti-Theft - Toggle

This disables the GM VAT system that uses the Key pellet. This should only be disabled with engine transplants to vehicles that don’t have the key pellet reader.

6 Speedometer

6.1 Gear_Tire Tab

Figure 18: Gear Tire Tab

The Gear_Tire Tab is dedicated to calibrating the speedometer.

Within the Gear_Tire Tab, you will find these three frames:

· Current Gear and Tire in PCM

· New Tire Size

· New Gear Ratio

6.1.1 Current Gear and Tire Frame

The “Current Gear and Tire in PCM” Frame, displays the gear Ratio, and tire size currently stored in the PCM.

6.1.2 New Tire Size Frame

The “New Tire Size” Frame, allows you to enter a new tire size, as a Tire Diameter, or the tire size.

6.1.3 New Gear Ratio

Note that the value in the New Gear Ratio Speedometer box is greyed out. It is read only. Only values that appear with a white background may be changed. The new gear ratio is entered in the white box. Also, be sure to apply changes by clicking on the “Apply Gear and Tire Scale” button before they take effect.

6.2 Speed Limiters Tab

The Speed Limiters Tab is dedicated to MPH at which you hit the hard limit and it turns off the fuel.

Within the Speed Limiters Tab, you may edit speed limit, electronic throttle, and hysteresis.

Figure 19: Speed Limiter Window

6.2.1 Limiters

7 Engine Diagnostic

7.1 Warning Tab

Changes to the Emissions related Diagnostic tests could be illegal in Street driven vehicles.

Figure 20: Diagnostic Warning Window

7.2 Hardware Diagnostics Tab

The hardware diagnostics tab is used to modify the Diagnostic tests in the PCM.

Figure 21: Hardware Diagnostics Window

7.2.1 Select Diagnostic Test

Use this pulldown window to select the diagnostic test that you want to examine

7.2.2 Enable Diagnostic Test

This window displays the current state of this diagnostic, Either On, or Off, and it can be toggled with the toggle button

7.2.3 Does Error Set SES

This window shows the current effect of this test on the MIL (malfunction indicator lamp).

Figure 22: Select Diagnostic Test Drop Down Menu

7.3 Test Parameter Tab

Figure 23 Engine Diagnostics Menu - Test Parameter Tab

7.3.1 Misfire detection

The Maximum Temperature and Minimum Temperature define the temperature range over which the test is run. You could make these both above the normal operating range, so the test isn’t run.

A better solution is to let the test run, but fine tune it so it doesn’t show misfire counts when the engine is running normally. That way if you crack a plug, or have an injector go bad, you will get an error code. When you put a large cam in these engines, the misfire test will falsely identify a misfire. You can loosen up the test at idle, and get rid of these errors. Set the test value in the idle and low RPM tables to 32000, This will loosen up the test, so it should always pass. The test at mid RPM will still be functional.

Appendix A: Glossary

AFR = Air Fuel Ratio

ALDL = Assembly Line Diagnostic Link. The connector under the dash on non-OBDII GM cars.

BLM = Block Learn Multiplier. A parameter in the fuel control strategy

DFCO = Deceleration Fuel Cut-Off

IAC = Idle Air Control. A motor controlled by the PCM. It determines how much air gets through to the engine at idle. The computer controls it to maintain a constant idle speed.

IAT = Intake Air Temperature

Kpa =Kilopascals is the measure of load

MAF = Mass Air Flow. The mass of air flowing into the intake is directly measured via a hot wire,

MAP = Manifold Absolute Pressure. The air pressure in the intake.

MIL = Malfunction Indicator Lamp. "Check engine" light.

PCM = Powertrain Control Module.

PE = Power Enrichment

TCC = Torque Converter Clutch

%TPS = Percent of Throttle Position Sensor

VAT = Vehicle Anti-Theft, This disables the GM VAT system that uses the Key pellet. This should only be disabled with engine is transplanted to vehicles that don’t have the key pellet reader.

VIN =: Vehicle Identification Number

VSS = Vehicle Speed Sensor

WOT = Wide Open Throttle