DTC U0122: Power Control Unit Lost Communication With VSA Modulator-Control Unit (VSA Message) (Keyless Access Power Control Unit) (2013-15)

DTC (Power Control Unit)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   - 2. Press the engine start/stop button to select the OFF 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 below.

   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 below.

   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. Press the engine start/stop button to select the OFF mode.

   - 2. Disconnect the following connector.

   VSA modulator-control unit 22P connector - Refer to: VSA Modulator-Control Unit Removal and Installation, or VSA Modulator-Control Unit Removal and Installation (With ACC) (2016-17)

   - 3. Press the engine start/stop button to select the ON mode.

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

   Test condition	ON mode VSA modulator-control unit 21P connector: disconnected
   Test circuit	IG1 VSA/ABS
   Test point 1	VSA modulator-control unit 21P connector No. 6 (YEL)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

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

   NO 

   Repair an open or high resistance in the wire.

4. Open wire check (GND line)

   -1. Press the engine start/stop button to select the OFF mode.

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

   Test condition	OFF mode VSA modulator-control unit 21P connector: disconnected
   Test circuit	GND
   Test point 1	VSA modulator-control unit 21P connector No. 1 (BLK)
   Test point 2	Body ground

   Test circuit	GND
   Test point 1	VSA modulator-control unit 21P connector No. 2 (BLK)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The GND wires are OK. Go to step 5 below.

   NO 

   Repair an open or high resistance in the ground wire or poor ground (G202).

5. Open wire check (F CAN lines)

   -1. Disconnect the following connector.

   Keyless access control unit connector C (24P)

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

   Test condition	OFF mode VSA modulator-control unit 21P connector: disconnected Keyless access control unit connector C (24P) : disconnected
   Test circuit	F CAN-H
   Test point 1	VSA modulator-control unit 21P connector No. 15 (WHT)
   Test point 2	Keyless access control unit connector C (24P) No. 4 (WHT)

   Test circuit	F CAN-L
   Test point 1	VSA modulator-control unit 21P connector No. 8 (RED)
   Test point 2	Keyless access control unit connector C (24P) No. 5 (RED)

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

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

   NO 

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