Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC B1318 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	INSPECT BATTERY VOLTAGE Is battery terminal voltage okay?	Yes	Make sure that battery terminal connection is okay. Go to the next step.
1	INSPECT BATTERY VOLTAGE Is battery terminal voltage okay?	No	Charge or replace battery, then go to Step 6.
2	INSPECT BATTERY GRAVITY Is battery specific gravity as specified?	Yes	Go to the next step.
2		No	Replace battery, then go to Step 6.
3	INSPECT CHARGING SYSTEM Are generator and drive belt tensions okay?	Yes	Go to the next step.
3		No	Adjust drive belt tension as necessary. Replace generator and/or drive belt as necessary.
4	INSPECT ABS/TCS HU/CM POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT Start engine. Measure voltage between ABS/TCS HU/CM terminal Z and ground. Is voltage above 10 V?	Yes	Go to the next step.
4		No	Go to Step 6.
5	INSPECT ABS/TCS HU/CM GROUND CIRCUIT FOR POOR GROUND OR OPEN CIRCUIT Turn the ignition switch off. Measure resistance between ground and ABS/TCS HU/CM terminal AC. Is resistance within 0-1 ohm?	Yes	Go to the next step.
5		No	If there is no continuity: Repair or replace harness for open circuit between ABS/ TCS HU/CM and ground, then go to the next step. If resistance is not within 0-1 ohm: Repair or replace harness for poor ground then go to the next step.
6	VERIFY TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the memory. (See CLEARING DTCS PROCEDURES ) Is same DTC present?	Yes	Replace ABS/TCS HU/CM, then go to the next step.
6		No	Go to the next step.
7	VERIFY AFTER REPAIR PROCEDURE Is there any other DTC present?	Yes	Go to the applicable DTC inspection.
7		No	Troubleshooting completed.