K 2500 Truck 4WD V8-6.5L DSL Turbo VIN S (1998)
Powertrain Control Module (PCM): Service and Repair
TDC Offset Program Procedure
The PCM will automatically activate the TDC Offset program when the engine coolant is greater than 77°C (170°F). If the PCM is not programmed
with a TDC Offset, a DTC P1214 will set.
This procedure should only be used when a DTC has directed you to or one of the following repairs has been performed:
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A DTC 1214 is set.
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The engine has been replaced.
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The front engine cover has been replaced.
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The PCM and the Injection pump have been replaced.
The PCM has the ability to perform a TDC Offset learn when one is not present or has been cleared. This procedure allows the PCM to be updated
with the correct TDC offset for the vehicle.
IMPORTANT: The TDC Offset specification is only to be used after the Clear and Learn procedure has been performed.
TDC Offset Specification -0.25 to -0.75.
CLEARING AND LEARNING TDC OFFSET
1. One of the above repairs has been performed. If not, do not continue. Refer to On Vehicle Service for repair that was performed.
2. Install the scan tool.
3. Start the engine.
4. Operate the vehicle until the engine coolant temperature is greater than 77°C (170°F).
5. Clear all DTCs.
6. Turn the Ignition ON with the engine OFF.
7. Hold the accelerator pedal in the wide open throttle position for a minimum of 45 seconds (this step prepares the PCM to activate the offset learn
(internal).
8. Turn the ignition OFF for 30 seconds. In this step, the PCM is being powered down.
9. Start the engine.
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Verify in the scan tool that ECT is greater than 77°C (170°F). If not, operate vehicle until desired ECT is achieved (vehicle can be driven or
throttle can be depressed until correct coolant temperature is achieved).
^
As soon as ECT is greater than 77°C (170°F) and the engine speed is below 1500 RPMs, the PCM automatically learns a new offset.
10. A new offset will over write the previous one. The TDC Offset should be between -0.25 and -0.75.If the TDC Offset is within the specified value,
the procedure is complete, If not, continue to the next step (adjusting the injection pump).
11. Turn the engine OFF.
