DTC B1262: A/C ECU Communication Stop: Procedure
- CHECK FUSE (A/C)
- Remove the A/C fuse from the cowl side J/B LH.
- Measure the resistance of the fuse.
Standard resistance
Below 1 Ω
NG → REPLACE FUSE
OK: Go to next step
- CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY AND BODY GROUND)
- Disconnect the J58 ECU connector.
- Measure the voltage and resistance of the wire harness side connector.
Standard voltage
Tester Connection Condition Specified Condition B (J58-1) - Body ground Always 10 to 14 V Standard resistance
Tester Connection Specified Condition GND (J58-20) - Body ground Below 1 Ω TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Air Conditioning Amplifier Assembly)
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- Disconnect the J58 ECU connector.
- CHECK RESISTANCE OF COMMUNICATION LINE
- Disconnect the J58, J34 and J76 ECU connectors.
- Measure the resistance of the wire harness side connector.
Standard resistance
Tester Connection Specified Condition MPX- (J58-31) - MPX+ (J34-6) Below 1 Ω MPX+ (J58-30) - MPI2 (J76-13) Below 1 Ω Result
Result Proceed to Both are OK A One is OK B Both are NG C TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Air Conditioning Amplifier Assembly)*2 Front view of wire harness connector
(to Combination Meter Assembly)*3 Front view of wire harness connector
(to Gateway ECU)
B → REPLACE AIR CONDITIONING AMPLIFIER AND REPAIR OR REPLACE HARNESS OR CONNECTOR
C → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
- Disconnect the J58, J34 and J76 ECU connectors.