DTC B1318 [BCM]SM2445880
DTC B1318 [BCM]

id0902f5831000

DTC B1318

Battery voltage low
DETECTION CONDITION
• Input voltage from the battery is excessively low.
POSSIBLE CAUSE
• PCM DTC is stored
• Battery malfunction
• Generator malfunction
• BCM connector or terminal malfunction
• Short to ground or open circuit in BCM power supply circuit
• BCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY PCM DTC
• Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L5].) (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].) (See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].)
• Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [L5].)
(See DTC TABLE [L3 Turbo].)
(See DTC TABLE [MZR-CD 2.2].)
No
Go to the next step.
2
INSPECT BATTERY
• Inspect the battery. (See BATTERY INSPECTION [L5].) (See BATTERY INSPECTION [L3 Turbo].) (See BATTERY INSPECTION [MZR-CD 2.2].)
• Is there any malfunction?
Yes
Recharge or replace the battery, then go to Step 6.
(See BATTERY RECHARGING [L5].)
(See BATTERY RECHARGING [L3 Turbo].)
(See BATTERY RECHARGING [MZR-CD 2.2].)
(See BATTERY REMOVAL/INSTALLATION [L5].)
(See BATTERY REMOVAL/INSTALLATION [L3 Turbo].)
(See BATTERY REMOVAL/INSTALLATION [MZR-CD 2.2].)
No
Go to the next step.
3
INSPECT GENERATOR
• Inspect the generator. (See GENERATOR INSPECTION [L5].) (See GENERATOR INSPECTION [L3 Turbo].) (See GENERATOR INSPECTION [MZR-CD 2.2].)
• Is there any malfunction?
Yes
Replace the generator, then go to Step 6.
(See GENERATOR REMOVAL/INSTALLATION [L5].)
(See GENERATOR REMOVAL/INSTALLATION [L3 Turbo].)
(See GENERATOR REMOVAL/INSTALLATION [MZR-CD 2.2].)
No
Go to the next step.
4
INSPECT BCM CONNECTOR CONDITION
• Turn the ignition switch to the LOCK position.
• Disconnect the negative battery cable.
• Disconnect the BCM connector.
• Inspect the connector and terminals for poor connection (such as damaged/pulled-out pins, and corrosion).
• Is there any malfunction?
Yes
Repair or replace the connector and/or terminal, then go to Step 6.
No
Go to the next step.
5
INSPECT BCM POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT
• BCM connector is disconnected.
• Reconnect the negative battery cable.
• Measure the voltage at BCM terminal 4B (wiring harness-side).
• Is the voltage B+?
Yes
Go to the next step.
No
Inspect the ROOM 15 A fuse.
• If the fuse is melt:
― Repair or replace the wiring harness for a possible short to ground.
― Replace the fuse.
• If the fuse is deterioration:
― Replace the fuse.
• If the fuse is normal:
― Repair or replace the wiring harness for a possible open circuit.
Go to the next step.
6
VERIFY TROUBLESHOOTING COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the BCM using the M-MDS. (See CLEARING DTC [BCM].)
• Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].)
• Is the same DTC present?
Yes
Replace the BCM.
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
No
DTC troubleshooting completed.