DTC Troubleshooting: U0122 (126), U1102 (126)

DTC U0122:  FCAN Malfunction (VSA-ECM/PCM)
  
  

NOTE:

1.Turn the ignition switch ON (II).

2.Clear the DTC with the HDS.

3.Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0122 or U1102 indicated?


YES - Go to 4.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the VSA control unit and the ECM/PCM.n


4.Turn the ignition switch OFF.

5.Jump the SCS line with the HDS.

6.Disconnect the VSA control unit 47P connector.

7.Disconnect ECM/PCM connector E (31P).

8.Check for continuity between ECM/PCM connector terminal E11 and body ground, and between terminal E24 and body ground individually.

 

Is there continuity?


YES - Repair short in the wire between the VSA control unit and the ECM/PCM (E11** (E24)*) then go to 19.


NO - Go to 9.


9.Check for continuity between ECM/PCM connector terminals E11 and E24.

 

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (E11**) and (E24*) then go to 19.


NO - Go to 10.


10.Connect the VSA control unit 47P connector terminals No. 2 and No. 6 with a jumper wire.

 

11.Check for continuity between ECM/PCM connector terminals E11 and E24.

 

Is there continuity?


YES - Go to 12.


NO - Repair open in the wire between the VSA control unit and the ECM/PCM (E11** (E24)*), then go to 19.


12.Check for continuity between VSA control unit 47P connector terminal No. 32 body ground.

 

Is there continuity?


YES - Go to 13.


NO - Repair open in the wire between the VSA control unit and G501, then go to 19.

13.Turn the ignition switch ON (II).

14.Measure voltage between VSA control unit 47P connector terminal No. 13 and body ground.

 

Is there battery voltage?


YES - Go to 15.


NO - Check the No. 4 ACG (10 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the No. 4 ACG (10 A) fuse and the VSA control unit, then go to 18.

15.Turn the ignition swith OFF.

16.Reconnect the VSA control unit 47P connector.

17.Measure resistance between ECM/PCM connector terminals E11 and E24.

 

Is there about 108-132 W at room temperature?


YES - Go to 24.


NO - Substitute a known-good VSA control unit, then go to 18 and recheck. If DTC U0122 or U1102 is not indicated, replace the original VSA control unit, then go to 18. If DTC U0122 or U1102 is indicated, then go to 24.


18.Turn the ignition switch OFF.

19.Reconnect all connectors.

20.Turn the ignition switch ON (II).

21.Reset the ECM/PCM with the HDS.

22.Do the ECM/PCM idle learn procedure.

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

Are any Temporary DTCs or DTCs indicated?


YES - If DTC U0122 or U1102 is indicated, check for poor connections or loose terminals at the VSA control unit and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n

24.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

25.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC U0122 or U1102 is indicated, check for poor connections or loose terminals at the VSA control unit and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n