Circuit Description
The powertrain control module (PCM) has four fuel injector driver circuits, each of which controls a fuel injector. The PCM monitors the current in each driver circuit and is able to control the driver circuit. The current through each driver can rise to a peak of 2 amps to quickly open the fuel injectors and can reduce to 1/2 amp to hold the fuel injectors open. This is called peak and hold. If the current cannot reach a 2 amp peak, a DTC is set. This DTC is also set if an fuel injector driver is shorted to voltage.
Conditions for Running the DTC
| • | Engine is running. |
| • | Battery voltage is more than 9 volts. |
Conditions for Setting the DTC
| • | Injector current is less than 4 amps. |
| Or |
| • | Injector current is continuously high. |
| • | Above conditions met for 7 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles. |
| • | The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame and Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn off after 3 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage will cause a DTC P0200 to set and will also cause a misfire due to an inoperative injector. The misfire DTC should also be set indicating a misfire.
Long Term and Short Term FT that are excessively high or low are a good indication that an injector is malfunctioning. Refer to Fuel Injector Balance Test to test for malfunctioning injectors.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step determines if the DTC P0200 is the result of a hard malfunction or an intermittent condition.
-
This step tests the harness wiring and for the PCM control of the fuel injectors by using a fuel injector test lamp. If the tests lamp blinks, this indicates that the PCM and the wiring to the fuel injectors are OK. Using the Fuel Injector Coil Test will test if the fuel injectors are malfunctioning.
-
This step narrows the malfunction down to just a few possibilities, whether the test lamp was ON steady or OFF while cranking the engine.
-
Because the test lamp was ON steady, the voltage to the fuel injector is OK, but the fuel injector driver circuit is grounded at all times. This step determines if the circuitry is shorted to ground or if the PCM is malfunctioning.
-
The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed
-
This step determines if the voltage is available to the fuel injector. The voltage is supplied through the fuel pump relay so that the engine must be cranked in order for you to see voltage at the fuel injector.
-
This step determines if the fuel injector driver circuit is open or shorted to voltage or if the PCM is malfunctioning.
-
Since the voltage is supplied to the fuel injector on a single circuit before the fuel injector harness, the malfunction may only be a poor connection or an open in the fuel injector harness. An open before the harness may result in a Cranks But Will Not Run complaint.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
2 | Attempt to start the engine. Does the engine start and run? | -- | ||||||
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset? | -- | Go to Diagnostic Aids | ||||||
Does the fuel injector test lamp blink on all tests? | -- | |||||||
Verify whether the fuel injector test lamp was OFF or ON steady in step 4 for the fuel injector connector that did not blink. Was the fuel injector test lamp ON steady while cranking the engine? | -- | |||||||
Does the test lamp illuminate? | -- | |||||||
7 |
Did you find and correct the condition? | -- | ||||||
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | -- | ||||||
Does the test lamp illuminate while cranking? | -- | |||||||
Does the test lamp illuminate while cranking? | -- | |||||||
Did you complete the repair? | -- | -- | ||||||
12 |
Did you find a problem? | -- | ||||||
13 |
Did you complete the repair? | -- | -- | |||||
14 | Repair the circuit as necessary. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||
15 |
Does the DTC reset? | -- | System OK |
