P0404
DTC P0404: EGR Valve Insufficient Lift**NOTE:
- Information marked with an asterisk (*) applies to '01-03 models.
- Information marked with double asterisks (**) applies to '04 models.
1. Reset the ECM/PCM.
2. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3. Test-drive the vehicle under load for about 10 minutes. Try to keep the engine speed in the 1,700 - 2,500 rpm range.
4. Check for a Temporary DTC with the HDS or a scan tool.
Is Temporary DTC P1491* (P0404)** indicated?
YES - Go to step 5.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminal at the EGR valve and at the ECM/PCM.
5. Turn the ignition switch OFF.
6. Disconnect the EGR valve 6P connector.
7. Start the engine and let it idle.
8. Measure voltage between EGR valve 6P connector terminals No. 4 and No. 6.
Is there battery voltage?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM,then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Go to step 9.
9. Turn the ignition switch OFF.
10. Turn the ignition switch ON (II).
11. Measure voltage between EGR valve 6P connector terminals No. 2 and No. 3.
Is there about 5 V?
YES - Go to step 13.
NO - Go to step 12.
12. Measure voltage between ECM/PCM connector terminals A10 and A20.
Is there about 5 V?
YES - Repair open in the wire between the EGR valve and the ECM/PCM (A10, A20).
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
13. Turn the ignition switch OFF.
14. At the sensor side, measure resistance between EGR valve 6P connector terminals No. 1 and No. 2.
Is there continuity or resistance of 100 kOhm or more?
YES - Replace the EGR valve.
NO - Go to step 15.
15. Measure resistance between EGR valve 6P connector terminals No. 1 and No. 3,
Is there 100 kOhm or more?
YES - Replace the EGR valve.
NO - Go to step 16.
16. Reconnect the EGR valve connector.
17. Turn the ignition switch ON (II).
18. Measure voltage between ECM/PCM connector terminals A10 and A13.
Is there about 1.2 V?
YES - Go to step 21.
NO - Go to step 19.
19. Turn the ignition switch OFF.
20. Check for continuity between ECM/PCM connector terminal A13 and body ground.
Is there continuity?
YES - Repair short in the wire between the EGR valve and the ECM/PCM (A13).
NO - Repair open in the wire between the EGR valve and the ECM/PCM (A13).
21. Turn the ignition switch OFF.
22. Disconnect the EGR valve 6P connector.
23. Connect the battery positive terminal to EGR valve 6P connector terminal No. 4 with a jumper wire.
24. Start the engine and let it idle, then connect the battery negative terminal to EGR valve 6P connector terminal No. 6 with a jumper wire.
Does the engine stall or run rough?
YES - Go to step 25.
NO - Replace the EGR valve.
25. Turn the ignition switch OFF.
26. Disconnect ECM/PCM connector B (24P).
27. Check for continuity between ECM/PCM connector terminal B14 and body ground.
Is there continuity?
YES - Repair short in the wire between the EGR valve and the ECM/PCM (B14).
NO - Go to step 28.
28. Connect EGR valve 6P connector terminal No. 4 to body ground with a jumper wire.
29. Check for continuity between ECM/PCM connector terminal B14 and body ground.
Is there continuity?
YES - Go to step 30.
NO - Repair open in the wire between the EGR valve and the ECM/PCM (B14).
30. Disconnect the jumper wire from the EGR valve 6P connector.
31. Check for continuity between EGR valve 6P connector terminal No. 6 and body ground.
Is there continuity?
YES - Update the ECM/PCM if it does not have the | latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair open in the wire between the EGR valve and G101.