DTC U0122: Power control unit lost communication with VSA modulator-control unit (VSA message)

DTC (Power Control Unit)

NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .

1. Problem verification:

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTCs with the HDS.

   - 3. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   - 4. Wait for at least 6 seconds.

   - 5. Check for DTCs with the HDS.

   DTC Description	DTC
   U0122 Power control unit lost communication with VSA modulator-control unit (VSA message)

   Is DTC U0122 indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

2. Fuse check:

   Check the following fuse.

   Fuse	No. C27 (7.5 A)
   Location	Under-dash fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 3.

   NO 

   Replace the fuse. If the fuse blows again, repair a short to ground in the No. C27 (7.5 A) fuse circuit.

3. Open wire check (IG1 VSA/ABS line):

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connector.

   VSA modulator-control unit 38P connector

   - 3. Turn the vehicle to the ON mode.

   - 4. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode. VSA modulator-control unit 38P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 36
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   The IG1 VSA/ABS wire is OK. Go to step 4.

   NO 

   Repair an open or high resistance in the wire.

4. Open wire check (GND lines):

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Check for continuity between test points 1 and 2 individually.

   Test condition	Vehicle OFF mode. VSA modulator-control unit 38P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 1
   Test point 2	Body ground

   Test point 1	VSA modulator-control unit 38P connector No. 3
   Test point 2	Body ground

   Is there continuity?

   YES 

   The GND wires are OK. Go to step 5.

   NO 

   Repair an open or high resistance in the ground wire(s) or poor ground (G201).

5. Open wire check (F-CAN lines):

   - 1. Disconnect the following connector.

   Keyless access control unit connector C (20P)

   - 2. Check for continuity between test points 1 and 2 respectively.

   Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Keyless access control unit connector C (20P): disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 26
   Test point 2	Keyless access control unit connector C (20P) No. 12

   Test point 1	VSA modulator-control unit 38P connector No. 38
   Test point 2	Keyless access control unit connector C (20P) No. 2

   Is there continuity?

   YES 

   The F-CAN wires are OK. Replace the keyless access control unit .

   NO 

   An open or poor connection in the wire(s).