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 and KOEO and KOER DTC P1409 is present, go to next step. If Continuous Memory DTC P1409 is present, go to step 7.
- DTC P1409: Measure Resistance Across EGRVR Solenoid
Disconnect EGRVR solenoid harness connector. Measure EGRVR solenoid resistance. If solenoid resistance reading is 26-40 ohms, go to next step. If solenoid resistance is not as specified, replace EGRVR solenoid. After repair, go to step 8. - Check VPWR Circuit Voltage At EGRVR Solenoid
Turn ignition on, engine off. Measure voltage between ground and VPWR circuit (White/Red wire) at EGRVR solenoid harness connector. See Figure. Turn ignition off. If voltage reading is more than 10.5 volts, go to next step. If voltage reading is 10.5 volts or less, repair open in VPWR circuit (Red/White wire) between EGRVR solenoid harness connector and PCM 104-pin harness connector terminal No. 71. See WIRING DIAGRAMS article. After repair, go to step 8. - Check EGRVR Circuit Resistance
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance of EGRVR circuit between breakout box terminal No. 79 (2.0L) or No. 47 (3.0L) and EGRVR solenoid harness connector (Violet wire). If resistance reading is less than 5.0 ohms, go to next step. If resistance reading is 5.0 ohms or more, repair open in EGRVR circuit (Violet wire) between EGRVR solenoid harness connector and PCM 104-pin harness connector terminal No. 79 (2.0L) or No. 47 (3.0L). After repair, go to step 8. - Check EGRVR Circuit For Short To Power In Harness
Turn ignition on, engine off. Measure voltage of EGRVR circuit between breakout box terminal No. 79 (2.0L) or No. 47 (3.0L) and negative battery post. If voltage reading is less than one volt, turn ignition off. Go to next step. If voltage reading is not as specified, repair short to power in Violet wire between EGRVR solenoid harness connector and PCM 104-pin harness connector terminal No. 79 (2.0L) or No. 47 (3.0L). After repair, go to step 8. - Check EGRVR Circuit For Shorts To Ground
Measure resistance between breakout box terminal No. 79 (2.0L) or No. 47 (3.0L) (EGRVR) and terminals No. 24 and 103 (PWR GND). If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 8. If resistance reading is not as specified, repair short in Violet wire between EGRVR solenoid harness connector and PCM 104-pin harness connector terminal No. 79 (2.0L) or No. 47 (3.0L). See WIRING DIAGRAMS article. After repair, go to step 8. - Wiggle EGRVR Solenoid While Monitoring VPWR
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance of EGRVR circuit between breakout box terminal No. 79 (2.0L) or No. 47 (3.0L) and terminal No. 24 (PWR GND). Voltage reading must be more than 10.5 volts. For an indication of a fault, look for this voltage to drop while performing following:- Lightly tap on EGRVR solenoid.
- Wiggle EGRVR solenoid connector.
- Grasp EGRVR solenoid connector and wiggle wires between solenoid and PCM.
If a fault is indicated, isolate fault and repair as necessary. After repair go to next step. If no fault is indicated, fault is intermittent. Refer to INTERMITTENT testing under SYSTEM TESTS .
- 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 present, trouble shooting is complete.