Acura TSX / Honda Accord CL. Manual - part 618

NO: Troubleshooting is complete.  

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

1. Turn the ignition switch ON (II).  

2. Clear the DTC with the HDS.  

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

Is DTC U0122 indicated? 

YES: Go to step 4.  

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

4. Check for DTCs in the DTCs MENU with the HDS. 

Is TCS DTC 86 indicated? 

YES: Go to step 5.  

NO: Go to step 9 .  

5. Turn the ignition switch OFF.  

6. Disconnect the VSA control unit 47P connector.  

7. Check for continuity between VSA control unit 47P connector terminals No. 14 and No. 30. 

Is there continuity? 

YES: Go to step 8.  

NO: Repair open in the wire between the VSA control unit No. 14 (No. 30 - CANL line) and 
the ECM/PCM E11 (E24 - CANL line), then go to step 14 . 

NOTE:

If DTC U0073 is stored at the same time as DTC U0122, troubleshoot DTC U0073 
first, then recheck for DTC U0122.

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX

  

 

Fig. 99: Checking For Continuity Between VSA Control Unit 47P Connector Terminals No. 
14 & No. 30 

8. Check for poor connection at the cabin wire harness/dashboard wire harness 20P connector. 

Is it OK? 

YES: Substitute a known-good VSA control unit, then go to step 14 and recheck. If no DTCs 
are indicated, replace the original VSA control unit, then go to step 14 .  

NO: Reconnect the cabin wire harness/dashboard wire harness 20P connector, then go to step 
14 .  

9. Turn the ignition switch OFF.  

10. Disconnect the VSA control unit 47P connector.  

11. Turn the ignition switch ON (II).  

12. Measure voltage between VSA control unit 47P connector terminal No. 38 and body ground. 

Is there battery voltage? 

YES: Go to step 13.  

NO: Check the No. 21 IG METER (7.5A) fuse in the under-dash fuse/relay box. If the fuse is 
OK, repair open in the wire between the No. 21 IG METER (7.5A) fuse and the VSA control 
unit, then go to step 14 . 

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX

  

 

Fig. 100: Measuring Voltage Between VSA Control Unit 47P Connector Terminal No. 38 & 
Body Ground 

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

Is there continuity? 

YES: Substitute a known-good VSA control unit, then go to step 14 and recheck. If no DTCs 
are indicated, replace the original VSA control unit, then go to step 14.  

NO: Repair open in the wire between the VSA control unit and G203, then go to step 14. 

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX

  

 

Fig. 101: Checking For Continuity Between VSA Control Unit 47P Connector Terminal No. 
32 & Body Ground 

14. Turn the ignition switch ON (II).  

15. Reset the ECM/PCM with the HDS.  

16. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).  

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

Are any Temporary DTCs or DTCs indicated? 

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

NO: Troubleshooting is complete.  

MIL CIRCUIT TROUBLESHOOTING 

1. Turn the ignition switch ON (II).  

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE PGM-FI System - TSX