Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Mazda Tribute. However, it is still accessible from the selected car via links, so may be relevant.
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- Check Injector Fault PIDS
Access INJ1F-INJ6F PIDs using scan tool. If an injector fault is present, go to next step. If an injector fault is not present, go to step 6.NOTE: Next step measures resistance of suspect fuel injector at breakout box terminals. Resistance measurement includes vehicle wiring harness and fuel injector. - Check Fuel Injector(s) & Harness Resistance
This erases Continuous Memory DTCs. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Use injector fault PID to determine fuel injector circuit(s) requiring testing. Measure resistance of fuel injector between suspect INJ circuit terminal and VPWR terminal No. 71 of breakout box. See Fig 1. If resistance reading is 11-18 ohms, replace PCM. After repair, go to step 6. If resistance reading is not as specified, go to next step. - Check Fuel Injector Harness Resistance
Disconnect fuel injector harness connector at suspect fuel injector. Measure resistance of VPWR circuit between breakout box terminal No. 71 and fuel injector harness connector terminal. See Fig 1. Measure resistance of INJ circuit between appropriate breakout box terminal and fuel injector harness connector terminal. If each resistance reading is less than 5 ohms, go to next step. If each resistance reading is 5 ohms or more, repair open circuit. After repair, go to step 6. - Check Fuel Injector Harness Circuit For Short To Power & Ground
Measure resistance between suspect INJ circuit terminal and VPWR terminal No. 71 of breakout box. Measure resistance between suspect INJ circuit terminal and PWR GND terminal No. 103 of breakout box. If each resistance reading is more than 10,000 ohms, replace PCM. Repeat QUICK TEST under SELF-DIAGNOSTIC SYSTEM. After repair, go to next step. If resistance reading is 10,000 ohms or less, repair short circuit. See WIRING DIAGRAMS article. After repair, go to next step. - Verify Trouble Shooting Of DTCs Completed
Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, procedure is complete.