B1262
Diagnostic trouble codes
DESCRIPTION
- This DTC is detected when communication between the air conditioning amplifier (A/C ECU) and gateway ECU stops for more than 10 seconds.
| DTC No. |
DTC Detection Condition |
Trouble Area |
| B1262 |
Air conditioning amplifier (A/C ECU) communication stops |
|
WIRING DIAGRAM


INSPECTION PROCEDURE
- HINT:
- When "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1262, repair the "+B or GND short malfunction of communication bus" DTCs first.
| 1. CHECK FUSE (A/C) |
Remove the A/C fuse from the main body ECU LH (cowl side J/B LH).
Measure the resistance of the fuse.
- Standard resistance:
- Below 1 Ω
|
|
||||
| OK | |
| 2. 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
|
|
||||
| OK | |
| 3. CHECK RESISTANCE OF COMMUNICATION LINE |
Disconnect the J58, A27, J34 and J76 ECU connectors.

Measure the resistance of the wire harness side connector.
- Standard resistance:
Tester Connection
Specified Condition
*1MPX- (J58-31) - MPX1 (A27-5)
Below 1 Ω
*2MPX- (J58-31) - MPX+ (J34-6)
Below 1 Ω
MPX+ (J58-30) - MPI2 (J76-13)
Below 1 Ω
- HINT:
- *1: w/ Adaptive front-lighting system
- *2: w/o Adaptive front-lighting system
- *1: w/ Adaptive front-lighting system
- Result:
Result
Proceed to
Both are OK
A
One is OK
B
Both are NG
C
|
|
||||
|
|
||||
| OK | ||
| ||
