DTC B1318: [Auto Light/Wiper Control Module]

DTC B1318 DETECTION CONDITION AND POSSIBLE CAUSE

DTC B1318	Battery voltage low
DETECTION CONDITION	Input voltage from the battery is excessively low
POSSIBLE CAUSE	Battery malfunction METER 10 A fuse Auto light/wiper control module connector malfunction Short to GND in wiring harness between auto light/wiper control module terminal 2C and battery Open circuit in wiring harness between auto light/wiper control module terminal 2C and battery Auto light/wiper control module malfunction
Courtesy of MAZDA MOTORS CORP.

DTC B1318 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	BATTERY INSPECTION Disconnect the battery cables. Refer to the battery inspection and inspect the battery. (Refer to BATTERY INSPECTION [13B-MSP] .) Is the battery normal?	Yes	Go to the next step.
1		No	Replace or charge the battery. (Refer to BATTERY REMOVAL/INSTALLATION [13B-MSP] .) (Refer to BATTERY RECHARGING [13B-MSP] .) Go to the Step 6.
2	FUSE INSPECTION Remove the METER 10 A fuse. Is the fuse normal?	Yes	Go to the next step.
2		No	Replace the fuse. After replacement, go to Step 6.
3	INSPECT AUTO LIGHT/WIPER CONTROL MODULE CONNECTOR Disconnect the auto light/wiper control module connector. Inspect the auto light/wiper control module connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion.) Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 6.
3		No	Go to the next step.
4	INSPECT AUTO LIGHT/WIPER CONTROL MODULE POWER SUPPLY CIRCUIT FOR SHORT TO GND Inspect for continuity between auto light/wiper control module terminal 2C (wiring harness-side) and body GND. Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to GND, then go to the Step 6.
4		No	Go to the next step.
5	INSPECT AUTO LIGHT/WIPER CONTROL MODULE POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT Install the METER 10 A fuse. Inspect for continuity between following terminals: Auto light/wiper control module terminal 2C and ignition switch terminal C. Ignition switch terminal F and battery positive terminal. Is there continuity?	Yes	Go to the next step.
5		No	Repair/replace the wiring harness. After repair procedure, go to the next step.
6	VERIFY DTC Reconnect the disconnected connectors and the negative battery cable. Clear DTCs using the M-MDS. (Refer to CLEARING DTC [AUTO LIGHT/WIPER CONTROL MODULE] .) Perform the auto light/wiper control module DTC inspection using the M-MDS. (Refer to DTC INSPECTION [AUTO LIGHT/WIPER CONTROL MODULE] .) Is DTC B1318 displayed?	Yes	Replace the auto light/wiper control module, then go to the next step. (Refer to AUTO LIGHT/WIPER CONTROL MODULE REMOVAL/INSTALLATION .)
6		No	Go to the next step.
7	VERIFY THAT NO OTHER DTCs ARE PRESENT Are there other DTCs output?	Yes	Perform the corresponding DTC inspection. (Refer to DTC TABLE [AUTO LIGHT/WIPER CONTROL MODULE] .)
7		No	DTC troubleshooting completed.