B1297

DESCRIPTION

This DTC is detected when communication between the clearance warning ECU and gateway ECU stops for more than 10 seconds.

DTC No.	DTC Detection Condition	Trouble Area
B1297	Clearance warning ECU communication stops	Clearance warning ECU Wire harness

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

When "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1297, repair the "+B or GND short malfunction of communication bus" DTCs first.

1. INSPECT FUSE (LH-IG)

1. Remove the LH-IG fuse from the main body ECU LH (cowl side J/B LH).

2. Measure the resistance of the fuse.

Standard resistance:

Below 1 Ω

NG	REPLACE FUSE

OK

Go to step 3

2. CHECK WIRE HARNESS (CLEARANCE WARNING ECU - BATTERY AND BODY GROUND)

1. Disconnect the Q37 ECU connector.

2. Measure the voltage and resistance of the wire harness side connector.

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   IG (Q37-8) - Body ground	Engine switch on (IG)	10 to 14 V

   Standard resistance:

   Tester Connection	Specified Condition
   E (Q37-27) - Body ground	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3. CHECK RESISTANCE OF COMMUNICATION LINE

1. Disconnect the Q37, A27, J58 and J34 ECU connectors.

2. Measure the resistance between the specified terminals on the wire harness side connectors.
   

   Standard resistance:

   with Adaptive Front-Lighting System: 

   Tester Connection	Specified Condition
   M+ (Q37-26) - MPX2 (A27-6)	Below 1 Ω
   M+ (Q37-26) - Body ground	10 kΩ or higher

   without Adaptive Front-Lighting System; 

   Tester Connection	Specified Condition
   M+ (Q37-26) - MPX- (J58-31)	Below 1 Ω
   M+ (Q37-26) - Body ground	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
REPLACE CLEARANCE WARNING ECU