DTC Troubleshooting: P0489 (12)

DTC P0489:  EGR Valve Circuit Low Voltage

1.Turn the ignition switch ON (II).

2.Do the DTC CLEAR in the CLEAR MENU with the HDS.

3.Do the EGR TEST in the INSPECTION MENU with the HDS.

Is the result OK?


YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the ECM.n


NO - Go to 4.


4.Turn the ignition switch OFF, and wait 10 seconds.

5.Disconnect the EGR valve 6P connector.

6.Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

7.Check for continuity between test pin box terminal No. 124 and body ground.

Is there continuity?


YES - Repair short in the wire between the ECM connector No. 5 terminal No. 3 (test pin box terminal No. 124) and the EGR valve, then go to 12.


NO - Go to 8.

8.At EGR valve side, check for continuity between EGR valve 6P connector terminal No. 4 and body ground.

 

Is there continuity?


YES - Go to 10.


NO - Go to 9.


9.At EGR valve side, measure resistance between EGR valve 6P connector terminals No. 4 and No. 6.

 

Is there about 6.3-6.7 W at room temperature?


YES - Go to 20.


NO - Go to 10.

10.Turn the ignition switch OFF.

11.Replace the EGR valve.

12.Reconnect all connectors.

13.Turn the ignition switch ON(II).

14.Do the ECM RESET in the CLEAR MENU with the HDS.

15.Do the ETCS learn procedure.

16.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in neutral) until the radiator fan comes on, then let it idle.

17.Do the EGR TEST in the INSPECTION MENU with the HDS.

18.Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0489 is indicated, check for poor connections or loose terminals at the EGR valve and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Go to 19.


19.Do the EGR TEST in the INSPECTION MENU with the HDS.

Is the result OK?


YES - Troubleshooting is complete.n


NO - Check for poor connections or loose terminals at the EGR valve and the ECM, then go to 16 and recheck.

20.Substitute a known-good ECM.

21.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in neutral) until the radiator fan comes on, then let it idle.

22.Do the EGR TEST in the INSPECTION MENU with the HDS.

23.Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0489 is indicated, check for poor connections or loose terminals at the EGR valve and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Replace the original ECM.n