DTC U0122: Power Control Unit Lost Communication with VSA Modulator-Control Unit (VSA Message) (L4, Keyless Access Power Control Unit) (2015-17)

DTC (Power Control Unit)

1. Problem verification

   -1. Clear the DTCs with the HDS.

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

   - 3. Wait for at least 6 seconds.

   - 4. 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

   -1. Check the following fuse.

   Fuse	No. B10 (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. B10 (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 - Refer to: VSA Modulator-Control Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector For Inputs And Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)
   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.

   Test condition	Vehicle OFF (LOCK) mode VSA modulator-control unit 38P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 1 - Refer to: VSA Modulator-Control Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector For Inputs And Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)
   Test point 2	Body ground

   Test point 1	VSA modulator-control unit 38P connector No. 3 - Refer to: VSA Modulator-Control Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector For Inputs And Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)
   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 or poor ground (G206).

5. Open wire check (F-CAN lines)

   -1. Connect terminals A and B with a jumper wire.

   Terminal A	VSA modulator-control unit 38P connector No. 38 - Refer to: VSA Modulator-Control Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector For Inputs And Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)
   Terminal B	VSA modulator-control unit 38P connector No. 26 - Refer to: VSA Modulator-Control Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector For Inputs And Outputs (Without Auto Idle Stop System) (2015-17) or VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)

   - 2. Disconnect the following connector.

   Keyless access/TPMS control unit connector C (20P)

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

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

   Is there continuity?

   YES 

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

   NO 

   An open or poor connection in the F-CAN wires between the VSA modulator-control unit and the keyless access/TPMS control unit.