C 1500 Truck 2WD V8-6.5L DSL Turbo VIN F (1998)
Crankshaft Position Sensor: Service and Repair
TDC Offset Program Procedure
TDC OFFSET PROGRAM PROCEDURE
This procedure should only be used when a Diagnostic Trouble Code (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 Powertrain Control Module (PCM) and the Injection pump have been replaced.
The PCM has the ability to perform a Top Dead Center (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).
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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.
12. Loosen injection pump flange nuts using J 41089.
13. Slightly (1 mm equals 2 degrees) rotate the injection pump (use tool J 29872 to rotate injection pump) and tighten injection pump flange nuts.
Rotate pump toward driver side; a positive (+) number, rotate toward passenger side (1 mm equals 2 degrees) in order to achieve a negative (-)
number.
14. Repeat steps 3 through 11 until correct TDC Offset has been achieved. Its possible that the injection pump may be adjusted multiple times until the
specified value is achieved.
IMPORTANT: If you are unable to set the correct TDC Offset, check the following:
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Check to see if coolant temperature is greater than 77°C (170°F).
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Check all PCM and injection timing stepper motor connections.
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Check the Techline terminal/equipment for the latest software version.
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Check for proper base installation of the injection pump (injection pump ESO solenoid should be approximately straight up and down).
NOTE: If all checks have been performed, the injection pump may be malfunctioning, however, this is an extremely unlikely failure.
