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 (TDC). This test compares desired timing to measured timing when certain conditions have been met. To retard injection timing, the powertrain control module (PCM) extends the stepper motor. To advance injection timing the PCM retracts the stepper motor. This is a type B diagnostic trouble code (DTC).
Conditions for Running the DTC
| • | The PCM performs this DTC diagnostic continuously. |
| • | DTCs P0251, P0335, or P0370 are 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 are met for 2 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
An intermittent may be caused by the following conditions:
| • | 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. DTC P0216 may set if the injection timing is not set correctly. Refer to Fuel Injection Pump Timing Adjustment for correct procedure.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step determines if DTC P0216 is a hard failure or an intermittent.
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This step checks for an open or short in the injection timing coil circuit 1.
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This step checks for an open or short in the injection timing coil circuit 2.
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The important thing in this step is that the PCM is sending a varying voltage (voltage may vary between 1-12. Usually you will see the voltage vary between 5-6 when the engine is idling), this will indicate that the PCM is OK and that there is a problem with the injection timing stepper motor. If there is a steady voltage present on any circuit, there is a short to voltage or internal PCM problem.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||
Does the scan tool display a difference more than or equal to the specified value between Actual Inj Time and Desired Inj Time at idle or at 2,700 RPM? | 5° | Go to Step 4 | Go to Step 3 | |||||
3 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored refer to those tables first. Are any additional DTCs stored? | -- | Go to Diagnostic Aids | |||||
Does the resistance measure within the specified value? | 10-60 ohms | Go to Step 5 | Go to Step 9 | |||||
Measure the resistance between ITS coil 2 low and ITS coil 2 high at the PCM harness. Does the resistance measure within the specified value? | 10-60 ohms | Go to Step 6 | Go to Step 10 | |||||
Does the voltage vary on all circuits? | -- | Go to Step 7 | Go to Step 12 | |||||
7 |
Does the resistance measure within the specified value? | 950-1,050 ohms | Go to Step 8 | Go to Step 13 | ||||
8 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 | ||||
9 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 11 | ||||
10 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 11 | ||||
11 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 | ||||
12 | Check the non-varying circuit for a short to ground, short to voltage, or a proper connection at the PCM. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 16 | ||||
13 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 | ||||
14 | Replace the crankshaft position sensor. Refer to Crankshaft Position Sensor Replacement . After replacing the sensor, the PCM must be programmed with a new offset. Refer to Fuel Injection Pump Top Dead Center Offset Adjustment . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||
15 |
Important: The new injection pump must be timed. Refer to Fuel Injection Pump Timing Adjustment . Replace the injection pump. Refer to Fuel Injection Pump Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||
16 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||
17 |
Does the DTC run and pass? | -- | Go to Step 18 | Go to Step 2 | ||||
18 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||
