DTC B257C [BCM]

id0902f5955900

Description | Front door lock-link switch (passenger-side)/rear door lock-link switch (LH)/(RH) circuit malfunction
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Detection condition | • Open circuit in front door lock-link switch (passenger-side), rear door lock-link switch (LH) or (RH) circuit with the door lock-link switches unlocked.
Possible cause | • Front door latch and lock actuator (passenger-side) connector or terminal malfunction • Open circuit in wiring harness between the following: ― Front door latch and lock actuator (passenger-side) terminal 2E—Body ground (L.H.D.) ― Front door latch and lock actuator (passenger-side) terminal 2B—Body ground (R.H.D.) • Front door lock-link switch (passenger-side) malfunction • BCM connector or terminal malfunction • Open circuit in wiring harness between the following terminals: ― Front door latch and lock actuator (passenger-side) terminal 2A—BCM terminal 1E (L.H.D.) ― Front door latch and lock actuator (passenger-side) terminal 2F—BCM terminal 1E (R.H.D.) • Rear door latch and lock actuator (LH) connector or terminal malfunction • Open circuit in wiring harness between rear door latch and lock actuator (LH) terminal 2B and body ground • Rear door lock-link switch (LH) malfunction • Open circuit in wiring harness between rear door latch and lock actuator (LH) terminal 2F and BCM terminal 6U • Rear door latch and lock actuator (RH) connector or terminal malfunction • Open circuit in wiring harness between rear door latch and lock actuator (RH) terminal 2E and body ground • Rear door lock-link switch (RH) malfunction • Open circuit in wiring harness between rear door latch and lock actuator (RH) terminal 2A and BCM terminal 6W • BCM malfunction

Diagnostic procedure

Step | Inspection | Action
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1 | VERIFY IF MALFUNCTION CAUSE IS FRONT DOOR LOCK-LINK SWITCH (PASSENGER-SIDE) CIRCUIT, REAR DOOR LOCK-LINK SWITCH (LH) CIRCUIT, (RH) CIRCUIT OR BCM • Operate the door lock-link switch to lock and unlock. • Do all door lock-link switch operate correctly? | Yes | Go to Step 20.
No | Front door lock-link switch (passenger-side) does not operate correctly: • Go to the next step. Rear door lock-link switch (LH) does not operate correctly: • Go to Step 8. Rear door lock-link switch (RH) does not operate correctly: • Go to Step 14. All door lock-link switches do not operate correctly: • Go to Step 20.
2 | INSPECT FRONT DOOR LATCH AND LOCK ACTUATOR (PASSENGER-SIDE) CONNECTOR • Turn the ignition switch to the OFF position. • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Disconnect the front door latch and lock actuator (passenger-side) connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is there any malfunction? | Yes | Repair or replace the connector, then go to Step 20.
No | Go to the next step.
3 | VERIFY IF MALFUNCTION CAUSE IS FRONT DOOR LOCK-LINK SWITCH (PASSENGER-SIDE) POWER SUPPLY CIRCUIT OR GROUND CIRCUIT • Verify that the front door latch and lock actuator (passenger-side) connector is disconnected. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Measure the voltage at the following terminal (wiring harness-side): ― Front door latch and lock actuator (passenger-side) terminal 2A (L.H.D.) ― Front door latch and lock actuator (passenger-side) terminal 2F (R.H.D.) • Is the voltage 0 V? | Yes | A malfunction in power supply circuit can be considered. • Go to Step 6.
No | A malfunction in ground circuit can be considered. • Go to the next step.
4 | INSPECT FOR OPEN CIRCUIT IN FRONT DOOR LOCK-LINK SWITCH (PASSENGER-SIDE) GROUND CIRCUIT • Verify that the front door latch and lock actuator (passenger-side) connector is disconnected. • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Inspect for continuity between the following terminal (wiring harness-side) and body ground: ― Front door latch and lock actuator (passenger-side) terminal 2E (L.H.D.) ― Front door latch and lock actuator (passenger-side) terminal 2B (R.H.D.) • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the wiring harness which has an open circuit, then go to Step 20.
5 | INSPECT FRONT DOOR LOCK-LINK SWITCH (PASSENGER-SIDE) • Inspect the front door lock-link switch (passenger-side). (See DOOR LOCK-LINK SWITCH INSPECTION.) • Is there any malfunction? | Yes | Replace the front door latch and lock actuator (passenger-side), then go to Step 20. (See FRONT DOOR LATCH AND LOCK ACTUATOR REMOVAL/INSTALLATION.)
No | Go to Step 20.
6 | INSPECT BCM CONNECTOR • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Disconnect the BCM connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is there any malfunction? | Yes | Repair or replace the connector, then go to Step 20.
No | Go to the next step.
7 | VERIFY IF MALFUNCTION CAUSE IS BCM OR FRONT DOOR LOCK-LINK SWITCH (PASSENGER-SIDE) POWER SUPPLY CIRCUIT • Reconnect the BCM connector. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Measure the voltage at the BCM terminal 1E (wiring harness-side). • Is the voltage 0 V? | Yes | A malfunction in BCM can be considered. • Go to Step 20.
No | A malfunction in power supply circuit can be considered. • Repair or replace the wiring harness which has an open circuit, then go to Step 20.
8 | INSPECT REAR DOOR LATCH AND LOCK ACTUATOR (LH) CONNECTOR • Turn the ignition switch to the OFF position. • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Disconnect the rear door latch and lock actuator (LH) connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is there any malfunction? | Yes | Repair or replace the connector, then go to Step 20.
No | Go to the next step.
9 | VERIFY IF MALFUNCTION CAUSE IS REAR DOOR LOCK-LINK SWITCH (LH) POWER SUPPLY CIRCUIT OR GROUND CIRCUIT • Verify that the rear door latch and lock actuator (LH) connector is disconnected. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Measure the voltage at the rear door latch and lock actuator (LH) terminal 2F (wiring harness-side). • Is the voltage 0 V? | Yes | A malfunction in power supply circuit can be considered. • Go to Step 12.
No | A malfunction in ground circuit can be considered. • Go to the next step.
10 | INSPECT FOR OPEN CIRCUIT IN REAR DOOR LOCK-LINK SWITCH (LH) GROUND CIRCUIT • Verify that the rear door latch and lock actuator (LH) connector is disconnected. • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Inspect for continuity between rear door latch and lock actuator (LH) terminal 2B (wiring harness-side) and body ground. • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the wiring harness which has an open circuit, then go to Step 20.
11 | INSPECT REAR DOOR LOCK-LINK SWITCH (LH) • Inspect the rear door lock-link switch (LH). (See DOOR LOCK-LINK SWITCH INSPECTION.) • Is there any malfunction? | Yes | Replace the rear door latch and lock actuator (LH), then go to Step 20. (See REAR DOOR LATCH AND LOCK ACTUATOR REMOVAL/INSTALLATION.)
No | Go to Step 20.
12 | INSPECT BCM CONNECTOR • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Disconnect the BCM connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is there any malfunction? | Yes | Repair or replace the connector, then go to Step 20.
No | Go to the next step.
13 | VERIFY IF MALFUNCTION CAUSE IS BCM OR REAR DOOR LOCK-LINK SWITCH (LH) POWER SUPPLY CIRCUIT • Reconnect the BCM connector. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Measure the voltage at the BCM terminal 6U (wiring harness-side). • Is the voltage 0 V? | Yes | A malfunction in BCM can be considered. • Go to Step 20.
No | A malfunction in power supply circuit can be considered. • Repair or replace the wiring harness which has an open circuit, then go to Step 20.
14 | INSPECT REAR DOOR LATCH AND LOCK ACTUATOR (RH) CONNECTOR • Turn the ignition switch to the OFF position. • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Disconnect the rear door latch and lock actuator (RH) connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is there any malfunction? | Yes | Repair or replace the connector, then go to Step 20.
No | Go to the next step.
15 | VERIFY IF MALFUNCTION CAUSE IS REAR DOOR LOCK-LINK SWITCH (RH) POWER SUPPLY CIRCUIT OR GROUND CIRCUIT • Verify that the rear door latch and lock actuator (RH) connector is disconnected. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Measure the voltage at the rear door latch and lock actuator (RH) terminal 2A (wiring harness-side). • Is the voltage 0 V? | Yes | A malfunction in power supply circuit can be considered. • Go to Step 18.
No | A malfunction in ground circuit can be considered. • Go to the next step.
16 | INSPECT FOR OPEN CIRCUIT IN REAR DOOR LOCK-LINK SWITCH (RH) GROUND CIRCUIT • Verify that the rear door latch and lock actuator (RH) connector is disconnected. • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Inspect for continuity between rear door latch and lock actuator (RH) terminal 2E (wiring harness-side) and body ground. • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the wiring harness which has an open circuit, then go to Step 20.
17 | INSPECT REAR DOOR LOCK-LINK SWITCH (RH) • Inspect the rear door lock-link switch (RH). (See DOOR LOCK-LINK SWITCH INSPECTION.) • Is there any malfunction? | Yes | Replace the rear door latch and lock actuator (RH), then go to Step 20. (See REAR DOOR LATCH AND LOCK ACTUATOR REMOVAL/INSTALLATION.)
No | Go to Step 20.
18 | INSPECT BCM CONNECTOR • Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Disconnect the BCM connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is there any malfunction? | Yes | Repair or replace the connector, then go to Step 20.
No | Go to the next step.
19 | VERIFY IF MALFUNCTION CAUSE IS BCM OR REAR DOOR LOCK-LINK SWITCH (RH) POWER SUPPLY CIRCUIT • Reconnect the BCM connector. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Measure the voltage at the BCM terminal 6W (wiring harness-side). • Is the voltage 0 V? | Yes | A malfunction in BCM can be considered. • Go to the next step.
No | A malfunction in power supply circuit can be considered. • Repair or replace the wiring harness which has an open circuit, then go to the next step.
20 | VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Reconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7].) • Clear the DTC for the BCM using the M-MDS. (See CLEARING DTC [BCM].) • Retrieve the BCM DTCs using the M-MDS. (See DTC INSPECTION [BCM].) • Is the same DTC displayed? | Yes | Repeat the inspection from Step 1. • If the malfunction recurs, replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.) Go to the next step.
No | Go to the next step.
21 | VERIFY IF OTHER DTCs DISPLAYED • Are any other DTCs displayed? | Yes | Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [BCM].)
No | DTC troubleshooting completed.