Diagnostic Procedures
WARNING: This page is about a different car, the 2003 Mazda MPV and 2002 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
- Record freeze frame data. Check for service bulletins and on-line information. Repair as necessary. After repair, go to next step.
- Classify Intermittent Concern Or Continuous Concern - Turn ignition off, then on (engine off). If no other DTCs are present, go to next step. If any other DTCs are present, repair those DTCs first. Refer to DIAGNOSTIC TROUBLE CODE IDENTIFICATION .
- Inspect Poor Connection Of EGR Valve - Turn ignition off. Disconnect EGR valve 6-pin harness connector. Check for damaged, loose or corroded terminals. If terminals and connector are okay, go to next step. If problem is present, repair terminal or connector as necessary. After repair, go to step 8.
- Inspect Power Circuit For Open Circuit - Turn ignition on, engine off. Measure voltage between ground and EGR valve terminals "C" and "D" individually. See Fig 1. If Battery voltage is present, go to next step. If battery voltage is not present, repair open in circuit between EGR valve 6-pin harness connector terminals "C" or "D" (White/Red wire) and main relay terminal "D" (Yellow wire). See appropriate wiring diagram under ENGINE PERFORMANCE in WIRING DIAGRAMS. After repair, go to step 8.
- Inspect EGR Valve -
Measure resistance between following EGR valve 6-pin connector terminals.
- Terminals "C" and "E".
- Terminals "C" and "A".
- Terminals "D" and "B".
- Terminals "D" and "F".
If resistance reading is about 22 ohms, go to next step. If resistance reading is not as specified, replace EGR valve. After repair, go to step 8.
- Inspect For Control Circuit For Short To Ground -
Check continuity in following circuits:
- EGR valve 6-pin harness connector terminal "E" and ground.
- EGR valve 6-pin harness connector terminal "A" and ground
- EGR valve 6-pin harness connector terminal "B" and ground.
- EGR valve 6-pin harness connector terminal "F" and ground.
If continuity is not present, go to next step. If continuity is present, repair short to ground in suspect circuit. Refer to EGR VALVE CIRCUIT IDENTIFICATION table. After repair, go to step 8.
EGR VALVE CIRCUIT IDENTIFICATIONEGR Valve Terminal Wire Color PCM Terminal No. "A" Pink/Black 72 "B" Black/Orange 46 "E" Red/Green 12 "F" Pink 56 - Inspect Control Circuit For Open Circuit -
Disconnect PCM 104-pin harness connector. Connect 104-pin Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Check continuity between following EGR valve 6-pin harness connector terminals and breakout box terminals:
- EGR valve terminal "A" and breakout box terminal No. 72.
- EGR valve terminal "B" and breakout box terminal No. 46.
- EGR valve terminal "E" and breakout box terminal No. 12.
- EGR valve terminal "F" and breakout box terminal No. 56.
If continuity is present, go to next step. If continuity is not present, repair open in suspect circuit between EGR valve 6-pin harness connector and PCM 104-pin harness connector. See EGR VALVE CIRCUIT IDENTIFICATION table. After repair, go to next step.
- Verify Trouble Shooting Of DTC P0403 Completed - Reconnect all connectors. Turn ignition off, then on (engine off). Using scan tool, check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If DTC P0403 is present, replace PCM. After repair, go to next step. If DTC P0403 is not present, go to next step.
- Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See AFTER REPAIR PROCEDURE . If no other DTCs are present, testing is complete. If any other DTC is present, go to applicable test and repair.