Diagnostic Procedure
WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
- If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
- Verify Related Repair Information Availability - Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
- Classify Intermittent Concern Or Continuous Concern - Turn ignition off, then on (engine off). If same DTC is present, go to next step. If same DTC is not present, problem is intermittent. Refer to INTERMITTENT PROBLEM DIAGNOSIS in TROUBLE SHOOTING - NO CODES article.
- Inspect EGR Valve Connector For Poor Connection - Turn ignition off. Disconnect EGR valve 6-pin harness connector. See Fig 1. Check for poor connection (such as damaged, pulled-out pins, and corrosion). If no malfunction is present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 10.
- Inspect EGR Valve Power Circuit For Open Circuit -
Turn ignition on, engine off. Measure voltage between following circuits:
- EGR valve 6-pin harness connector terminal "C" (White wire) and body ground
- EGR valve 6-pin harness connector terminal "D" (White wire) and body ground
- Inspect EGR Valve Control Circuit For Short To Ground -
Turn ignition off. Check for continuity between following circuits:
- EGR valve 6-pin harness connector terminal "A" (Pink wire) and body ground
- EGR valve 6-pin harness connector terminal "B" (Gray wire) and body ground
- EGR valve 6-pin harness connector terminal "E" (Red/Green wire) and body ground
- EGR valve 6-pin harness connector terminal "F" (Yellow wire) and body ground
- Inspect EGR Valve - Inspect EGR valve. Refer to EXHAUST GAS RECIRCULATION SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If EGR valve is okay, go to next step. If EGR valve is faulty, replace EGR valve. After repair, go to step 10.
- Inspect PCM Connector Terminal For Poor Connection - Turn ignition off. Disconnect PCM 104-pin harness connector. Inspect for poor connection (such as damaged, pulled-out pins, corrosion). If malfunction is not present, go to next step. If any malfunction is present, repair or replace terminal. After repair, go to step 10.
- Inspect EGR Valve Control Circuit For Open Circuit -
Turn ignition off. Check for continuity between following circuits:
- EGR valve 6-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 72 (Pink wire)
- EGR valve 6-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 46 (Gray wire)
- EGR valve 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 12 (Red/Green wire)
- EGR valve 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 56 (Yellow wire)
- Verify Trouble Shooting Of DTC P0403 Is Completed - Make sure to reconnect all disconnected connectors. Turn ignition on, engine off. If same DTC is not present, go to next step. If same DTC is present, replace PCM. For PCM removal and installation, see POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
- Verify After Repair Procedure - Using scan tool, perform After Repair Procedure. See AFTER REPAIR PROCEDURE . If any DTCs are present, go to appropriate DTC inspection. Refer to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are present, trouble shooting is complete.