Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
- A short to battery voltage or ignition 1 voltage on the MAP sensor signal circuit will disable the injector control circuits.
- Monitoring the fuel injector circuit status with a scan tool, while moving the fuel injector harness, may help isolate an intermittent condition.
- Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to Fuel Injector Coil Test .
- For an intermittent condition, refer to Intermittent Conditions .
Fuel Injector Circuit Diagnosis
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views |
|||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 | Is DTC P0201, P0202, P0203, P0204, P0205, or P0206 set? | Go to DTC P0201-P0206 | Go to Step 3 |
| 3 |
|
Go to Step 4 | Go to Step 6 |
| 4 | Test for continuity between the ignition 1 voltage circuit terminal and a fuel injector terminal, at the multi-way harness connector, fuel injector side. Refer to Testing for Continuity
in Wiring Systems. Does the DMM display OL? |
Go to Step 7 | Go to Step 5 |
| 5 | Test for an intermittent and for a poor connection at the multi-way harness connector. Refer to Connector Repairs
and Testing for Intermittent Conditions and Poor Connections
in Wiring Systems. Did you find and correct the condition? |
Go to Step 8 | Go to Diagnostic Aids |
| 6 | Repair the open in the ignition 1 voltage circuit between the PCM 1 fuse and the multi-way connector. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 8 | - |
| 7 | Repair the open or high resistance in the ignition 1 voltage circuit of the fuel injectors between the multi-way connector and the splice. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 8 | - |
| 8 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |