DTC U1281 (I-A3), U128D (I-A2), U1290 (I-A6), I-A4
DTC U1281 or DTC screen I-A3 : Climate Control Unit Lost Communication With MICU
DTC U128D or DTC screen I-A2 : Climate Control Unit Lost Communication With Gauge Control Module
DTC U1290 or DTC screen I-A6 : Climate Control Unit Lost Communication With Seat Heater Control Unit
DTC screen I-A4 : Climate Control Unit Lost Communication With Audio-navigation Unit
- According to the detected DTC(s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the climate control unit.
- Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.
| DTC Description | DTC |
|---|---|
| U1281 Climate Control Unit Lost Communication with MICU | |
| U128D Climate Control Unit Lost communication with gauge control module | |
| U1290 Climate Control Unit Lost Communication With Seat Heater Control Unit |
DTC (AC)
- Problem verification
-1. Clear the DTCs with the HDS.
-2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
-3. Do the Self-Diagnostic Function with the climate control unit .
-4. Wait for at least 6 seconds.
-5. Check for the climate control unit DTCs.
DTC Description DTC U1281 Climate Control Unit Lost Communication with MICU U128D Climate Control Unit Lost communication with gauge control module U1290 Climate Control Unit Lost Communication With Seat Heater Control Unit Is DTC U1281, U128D, U1290 or Error on the DTC screen I-A2, I-A3, I-A4, I-A6 indicated?
YES
Go to step 2.
NO
Intermittent failure, the system is OK at this time.
- Open wire check (B-CAN_H line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connectors.
DTC Connector U1281 (I-A3) Body control module connector B (36P) U128D (I-A2) Gauge control module connector A (32P) U1290 (I-A6) Front seat heater control unit 14P connector I-A4 Audio-navigation unit connector A (24P) - Climate control unit connector A (32P) -3. Check for continuity between the receiving control unit and the transmitting control unit on the B-CAN_H circuit.
Test condition Vehicle OFF (LOCK) mode Climate control unit connector A (32P): disconnected Transmitting control unit connector(s) for indicated DTCs: disconnected DTC Connector Terminal U1281 (I-A3) Body control module connector B (36P) No. 20 U128D (I-A2) Gauge control module connector A (32P) No. 30 U1290 (I-A6) Front seat heater control unit 14P connector No. 11 I-A4 Audio-navigation unit connector A (24P) No. 14 - Climate control unit connector A (32P) No. 28 Is there continuity?
YES
Go to step 3.
NO
Repair an open in the B-CAN_H wire between the climate control unit and the transmitting control unit.
- Open wire check (B-CAN_L line)
-1. Check for continuity between the receiving control unit and the transmitting control unit on the B-CAN_L circuit.
Test condition Vehicle OFF (LOCK) mode Climate control unit connector A (32P): disconnected Transmitting control unit connector(s) for indicated DTCs: disconnected DTC Connector Terminal U1281 (I-A3) Body control module connector B (36P) No. 21 U128D (I-A2) Gauge control module connector A (32P) No. 31 U1290 (I-A6) Front seat heater control unit 14P connector No. 10 I-A4 Audio-navigation unit connector A (24P) No. 24 - Climate control unit connector A (32P) No. 11 Is there continuity?
YES
Replace the climate control unit .
NO
Repair an open in the B-CAN_L wire between the climate control unit and the transmitting control unit.