Circuit Description
The PCM controls the fuel injector control circuit using a Multi Function Driver (MFD). The MFD has the ability to detect an electrical malfunction. If an electrical malfunction is detected, the MFD signals the PCM to set DTC P0203.
Conditions for Setting the DTC
| • | An incorrect voltage level is being detected on an injector driver circuit. |
| • | Above condition for over 30 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic runs and fails. |
| • | If equipped with traction control, the PCM will command the EBTCM via the serial data circuit to turn OFF traction control and illuminate the TRACTION OFF lamp. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed. |
| • | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool. |
Diagnostic Aids
Monitor the injector fault parameter in the scan tool. Wiggle the electrical harnesses for the effected electrical circuit. If the status changes on the scan tool, that may be an indicator where an intermittent fault may be located.
Check for the following conditions:
| • | Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the circuit |
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
If the scan tool indicates STUCK HIGH there is a short to battery positive voltage on the fuel injector driver circuit.
-
If the scan tool indicates STUCK LOW there is an open or a short to ground on the fuel injector driver circuit.
-
When the 10-way fuel injector connector is disconnected, DTCs P0107 and P1107 will be set. There DTCs should be disregarded.
If the scan tool indicates a STUCK HIGH while cranking, the short to battery positive voltage is between the 10-way connector and the PCM. If the scan tool indicates STUCK LOW while cranking the short to battery positive voltage is between the 10-way connector and the fuel injector.
Important: While cranking the engine with the 10-way fuel injector connector disconnected, all of the other injector circuits will indicate STUCK LOW, this is a fault induced by disconnecting the 10-way. They will resume correct operation when the 10-way connector is reconnected.
-
This step is checking for a short to ground in the circuit.
-
The fuel injector in this circuit will need to be checked after the short to ground is repaired or after the PCM is replaced.
-
This step is checking the function of the PCM. If the test lamp flashes then the PCM is able to supply the ground.
-
This vehicle is equipped with a PCM which utilizes an Electronically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the On Board Diagnostic (OBD) System Check performed? | Go to Step 2 | ||
2 | With the engine idiling monitor specific DTC P0203 on the scan tool. Does scan tool indicate DTC P0203 failed this ign? | |||
3 |
Does scan tool indicate P0203 failed this ignition? | Go to Diagnostic Aids | ||
Using the scan tool, enter output driver data menu. Does scan tool indicate cylinder number 3 injector circuit is STUCK HIGH? | ||||
Does the scan tool indicate cylinder number 3 injector circuit is STUCK LOW? | Go to Diagnostic Aids | |||
|
Important: While cranking the engine with the 10-way fuel injector connector disconnected, all of the other injector circuits will indicate Stuck Low, this is a fault induced by disconnecting the 10-way. They will resume correct operation when the 10-way connector is reconnected.
While cranking engine, does the scan tool indicate cylinder number 3 injector circuit is STUCK HIGH? | ||||
7 |
Does cylinder number 3 injector control circuit measure near specified value? | B+ | ||
8 | Locate and repair short to voltage in cylinder number 3 fuel injector control circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete | -- | ||
9 | Did the scan tool indicate the number 3 injector control circuit is STUCK LOW? | Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) | -- | |
Is the test lamp ON? | ||||
Is the test lamp ON? | ||||
With the test lamp still connected, crank the engine. Does the test lamp flash? | Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) | |||
13 |
Was a problem found? | -- | ||
14 | Locate and repair short to ground in the fuel injector driver circuit between the PCM and the 10-way fuel injector connector. Is action complete? | -- | ||
Replace the PCM. Important: : The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming Is the action complete? | -- | |||
16 |
Does the scan tool indicate DTC P0203 failed this ignition? | System OK |
