DTC U1281, U128D (Keyless Access Control Unit)
DTC U1281 : Keyless access control unit lost communication with MICU
DTC U128D : Keyless access control unit lost communication with gauge control module
NOTE:
- Refer to the DTC code shown on the display, and then inspect the connectors and terminals based on the instructions in the table below.
- The DTC may be stored due to the grounding failure or the power source failure at the transmitting control unit (the grounding inspection and the power source inspection on each control unit are required prior to this checking process).
| DTC Description | DTC |
|---|---|
| U1281 Keyless access control unit lost communication with MICU | |
| U128D Keyless access control unit lost communication with gauge control module |
DTC (Keyless Access Control Unit)
NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
- Problem verification
-1. Clear the DTCs with the HDS.
Clear DTCs
-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 U1281 Keyless access control unit lost communication with MICU U128D Keyless access control unit lost communication with gauge control module Are DTC U1281 or U128D indicated?
YES
Go to step 2.
NO
Intermittent failure, the system is OK at this time. Check for loose or poor connections.
- Open wire check (B-CAN_H, B-CAN_L lines)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the receiving control unit connector.
Keyless access/TPMS control unit connector C (20P) -3. Disconnect the transmitting control unit connectors.
Gauge control module 32P connector Under-dash fuse/relay box connector M (12P) -4. Check for continuity between the receiving control unit and the transmitting control unit on the B-CAN_H circuit and the B-CAN_L circuit as specified in the table while in the vehicle OFF (LOCK) mode.
DTC CIRCUIT NAME RECEIVING CONTROL UNIT TRANSMITTING CONTROL UNIT U1281 B-CAN_H Keyless access/TPMS control unit connector C (20P) No. 1 Under-dash fuse/relay box connector M (12P) No. 7 B-CAN_L Keyless access/TPMS control unit connector C (20P) No. 11 Under-dash fuse/relay box connector M (12P) No. 1 U128D B-CAN_H Keyless access/TPMS control unit connector C (20P) No. 1 Gauge control module 32P connector No. 26 B-CAN_L Keyless access/TPMS control unit connector C (20P) No. 11 Gauge control module 32P connector No. 27 Is there continuity?
YES
The B-CAN_L to B-CAN_H wire is OK. Go to step 3.
NO
Repair an open or high resistance in the wire(s).
- Determine possible failure area (the receiving control unit or the transmitting control unit)
-1. Reconnect all connectors.
-2. Clear the DTCs with the HDS.
Clear DTCs
-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 U1281 Keyless access control unit lost communication with MICU U128D Keyless access control unit lost communication with gauge control module Are DTC U1281 and U128D indicated?
YES
Check for loose terminals and poor connections in the keyless access/TPMS control unit connector. Check is OK, replace the keyless access/TPMS control unit .
NO
The keyless access/TPMS control unit is OK at this time. Replace the transmitting control unit.
(Refer to the DTC code shown on the display, and then replace the control unit based on the instructions in the table below.)
DTC TRANSMITTING CONTROL UNIT U1281 Replace the MICU U128D Replace the gauge control module