GM/Detroit 6.5L ENGINE CONTROLS – DTC P0216 Injection Timing Control Circuit

Circuit Description
Timing of the combustion event is accomplished by delivering a pulse of fuel into the combustion chamber at a desired degree of piston travel. This desired degree (desired timing), defines the current position of the piston in relationship of Top Dead Center. This test compares desired timing to measured timing when certain conditions have been met. To retard injection timing the PCM extends the stepper motor. To advance injection timing the PCM retracts the stepper motor. This is a type B DTC.

Conditions for Running the DTC
• The PCM performs this DTC diagnostic continuously.
• DTCs P0251, P0335 and P0370 not set.
• The engine speed has not changed more than 56 RPM for 5 seconds.

Conditions for Setting the DTC
• A 5 degree difference between Act. Inj. Time and Des. Inj. Time
• All of the diagnostic set conditions met for 2 seconds.

Action Taken When the DTC Sets
• The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails.
• The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the Failure Records will store this information. If the diagnostic reports a failure on the second consecutive drive trip, the Freeze Frame records the operating conditions at the time of failure and updates the Failure Records.

Conditions for Clearing the MIL/DTC
• The PCM will turn the MIL off after three consecutive trips without a fault condition.
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures
• The use of a scan tool.

Diagnostic Aids
An intermittent may be caused by the following:
• Poor connections
• Rubbed through wire insulation
• Broken wire inside the insulation
A hard start and possible poor performance condition might exist. Act. Inj. Time will freeze at the point of the fault. Its possible DTC P0216 will set if injection timing is not set correctly. Refer to Injection Timing Adjustment for correct procedure.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. This step determines if DTC P0216 is a hard failure or an intermittent.
4. This step checks for an open or short in the injection timing coil circuit 1.
5. This step checks for an open or short in the injection timing coil circuit 2.
6. The important thing in this step is that the PCM is sending a varying voltage (voltage may vary between 1 and 12 (usually you will see voltage vary between 5 and 6 when engine is idling)), this will indicate that the PCM is O K and that there is a problem with the injection timing Stepper motor. If there is a steady voltage present on any circuit, this will indicate a problem with the PCM or a circuit shorted to voltage.


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