DTC : B12D1

DTC B12D1  : Power Control Unit IG1B Circuit Error

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 - Go to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .
• Before troubleshooting, make sure the No. C39 (7.5 A) fuse in the under-dash fuse/relay box is OK.
• Make sure aftermarket accessories are not installed.

1. Problem verification

   - 1. Clear the DTCs with the HDS.

   Clear DTCs

   - 2. Turn the vehicle to the ON mode.

   - 3. Wait 10 seconds.

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

   - 5. Wait 5 seconds.

   - 6. Check for DTCs with the HDS.

   DTC Description	DTC
   B12D1 Power Control Unit IG1B Circuit Error

   Is DTC B12D1 indicated?

   YES 

   Go to step 2.

   NO 

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

2. Determine possible failure area (IG1B relay circuit ON problem, IG1B relay circuit OFF problem)

   -1. Turn the vehicle to the ON mode.

   - 2. Check the parameter(s) below with the HDS.

   Signal	Current conditions
   	Value	Unit
   IG1B

   - 3. Check the IG1B with the HDS.

   Is there battery voltage?

   YES 

   Go to step 3.

   NO 

   Go to step 4.

3. IG1B relay test

   -1. Do the IG1B relay test.

   Power Relay (2016 2017 2018) or

   Power Relay (2019 2020 2021) .

   Is IG1B relay OK?

   YES 

   Repair a short to power in the IG1B FBK wire between the under-dash fuse/relay box and the keyless access/TPMS control unit.

   NO 

   Faulty IG1B relay, replace the IG1B relay.

4. IG1B relay test

   -1. Do the IG1B relay test.

   Power Relay (2016 2017 2018) or

   Power Relay (2019 2020 2021) .

   Is IG1B relay OK?

   YES 

   Repair an open or high resistance in the IG1B FBK wire between the under-dash fuse/relay box and the keyless access/TPMS control unit.

   NO 

   Faulty IG1B relay, replace the IG1B relay.