Pinpoint Test B: DTC B1318
Anti-Lock Control - Three-Channel
Pinpoint Tests
Pinpoint Test B: DTC B1318
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
- DTC B1318 (Battery Voltage Low) - sets in continuous memory and on-demand if the ABS module detects that the battery voltage dropped below 9 volts on the voltage supply circuit when the vehicle speed was greater than 5 km/h (3 mph).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Charging system concern
- ABS module
PINPOINT TEST B: DTC B1318
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed results in false resistance readings. Refer to Battery, Mounting and Cables Battery Disconnect / Connect.
-------------------------------------------------
B1 RECHECK THE ABS MODULE DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: ABS Module Self-Test.
- Clear the DTCs. Repeat the ABS module self-test.
- Is DTC B1318 still present?
Yes
GO to B2.
No
The system is operating correctly at this time. The DTC may have been set due to a previous low battery voltage condition.
-------------------------------------------------
B2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM
- Enter the following diagnostic mode on the scan tool: PCM Self-Test.
- Retrieve the continuous memory DTCs from all modules.
- Is DTC P0620, P0622, P0625, P0626 or P065B set in the PCM?
Yes
REFER to Charging System Testing and Inspection.
No
GO to B3.
-------------------------------------------------
B3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE
- Check the battery condition and verify that the battery is fully charged. Refer to Battery, Mounting and Cables Testing and Inspection.
- Is the battery OK and fully charged?
Yes
GO to B4.
No
REFER to Battery, Mounting and Cables Testing and Inspection.
-------------------------------------------------
B4 CHECK THE VOLTAGE TO THE ABS MODULE
- Ignition OFF.
- Disconnect: ABS Module C135.
- Ignition ON.
- Measure the voltage between the ABS module and ground as follows:
- Are the voltages greater than 10 volts?
Yes
GO to B5.
No
For circuit SBB96 (VT/RD), VERIFY Battery Junction Box (BJB) fuse 96 (50A) is OK.
For circuit SBB86 (BN/RD), VERIFY BJB fuse 86 (25A) is OK.
For circuit CBB54 (VT/OG), VERIFY BJB fuse 54 (10A) is OK.
If the fuses are OK, REPAIR the affected circuits.
If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. Diagrams By Number
-------------------------------------------------
B5 CHECK CIRCUIT GD163 (BK/GY) FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the ABS module C135-13, circuit GD163 (BK/GY), harness side and ground; and between the ABS module C135-38, circuit GD163 (BK/GY), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
GO to B6.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
B6 CHECK THE ABS MODULE GROUND EYELET AT THE CHASSIS
- Remove the bolt retaining G135 on the LT frame rail.
- Clean the body mating surface and ground eyelets.
- Install the ground eyelet to the chassis with the retaining bolt.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: ABS Module Self-Test.
- Is the concern still present?
Yes
GO to B7.
No
The concern was caused by a loose or corroded connector. CLEAR the DTCs. REPEAT self-test.
-------------------------------------------------
B7 CHECK THE ABS MODULE CONNECTORS
- Disconnect the ABS module connector.
- Check for:
- corrosion
- pushed-out pins
- spread terminals
- Connect the ABS module connector and make sure that it is seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
-------------------------------------------------