DTC C0023:14 [BCM]

id0902f5070600

Description

Brake light circuit malfunction
Detection condition
•  BCM detects any of the following conditions:
―  Brake lights/high-mount brake light illuminated even though driver or system does not illuminate brake lights/high-mount brake lights.
―  Brake lights/high-mount brake light not illuminated even though driver depresses brake pedal.
―  Brake lights/high-mount brake light not illuminated even though system illuminates brake lights/high-mount brake light.
Fail-safe
•  Turn the brake light off.
Possible cause
•  Brake light bulb (LH) malfunction
•  Brake light bulb (RH) malfunction
•  High-mount brake light connector or terminal malfunction
•  Brake light (LH) connector or terminal malfunction
•  Brake light (RH) connector or terminal malfunction
•  BCM connector or terminal malfunction
•  Short to ground in wiring harness between the following terminals:
―  4SD:
•  Brake light (LH) terminal C—BCM terminal 2AB
•  Brake light (RH) terminal C—BCM terminal 2AB
•  High-mount brake light terminal B—BCM terminal 2AB
―  5HB:
•  Brake light (LH) terminal B—BCM terminal 2AB
•  Brake light (RH) terminal B—BCM terminal 2AB
•  High-mount brake light terminal A—BCM terminal 2AB
•  Short to power supply in wiring harness between the following terminals:
―  4SD:
•  Brake light (LH) terminal C—BCM terminal 2AB
•  Brake light (RH) terminal C—BCM terminal 2AB
•  High-mount brake light terminal B—BCM terminal 2AB
―  5HB:
•  Brake light (LH) terminal B—BCM terminal 2AB
•  Brake light (RH) terminal B—BCM terminal 2AB
•  High-mount brake light terminal A—BCM terminal 2AB
•  Open circuit in wiring harness between the following terminals:
―  4SD:
•  Brake light (LH) terminal C—BCM terminal 2AB
•  Brake light (RH) terminal C—BCM terminal 2AB
•  High-mount brake light terminal B—BCM terminal 2AB
―  5HB:
•  Brake light (LH) terminal B—BCM terminal 2AB
•  Brake light (RH) terminal B—BCM terminal 2AB
•  High-mount brake light terminal A—BCM terminal 2AB
•  High-mount brake light malfunction
•  Brake light (LH) malfunction
•  Brake light (RH) malfunction
•  BCM malfunction

Diagnostic Procedure

Step

Inspection

Action
1
VERIFY REAR BODY CONTROL MODULE (FBCM) DTCs AGAIN
•  Clear the DTC for the BCM using the M-MDS.
•  Depress the brake pedal.
•  Retrieve the BCM DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
With rear combination light (bulb type):
•  Go to the next step.
With rear combination light (LED type):
•  Go to Step 4.
No
Go to Step 18.
2
VISUALLY INSPECT BRAKE LIGHT BULB (LH)
•  Visually inspect the brake light bulb (LH)
•  Is the brake light bulb (LH) normal?
Yes
Go to the next step.
No
Replace the brake light bulb (LH), then go to Step 17.
(See BRAKE LIGHT/TAILLIGHT BULB REMOVAL/INSTALLATION.)
3
VISUALLY INSPECT BRAKE LIGHT BULB (RH)
•  Visually inspect the brake light bulb (RH)
•  Is the brake light bulb (RH) normal?
Yes
Go to the next step.
No
Replace the brake light bulb (RH), then go to Step 17.
(See BRAKE LIGHT/TAILLIGHT BULB REMOVAL/INSTALLATION.)
4
INSPECT HIGH-MOUNT BRAKE LIGHT CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the high-mount brake light connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 17.
5
INSPECT BRAKE LIGHT (LH) CONNECTOR CONDITION
•  Disconnect the brake light (LH) connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 17.
6
INSPECT BRAKE LIGHT (RH) CONNECTOR CONDITION
•  Disconnect the brake light (RH) connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 17.
7
INSPECT BCM CONNECTOR CONDITION
•  Disconnect the BCM connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 17.
8
INSPECT BRAKE LIGHT CIRCUIT FOR SHORT TO GROUND
•  Verify that the high-mount brake light, brake light (LH), brake light (RH) and BCM connectors are disconnected.
•  Inspect for continuity between BCM terminal 2AB (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  4SD:
―  Brake light (LH) terminal C—BCM terminal 2AB
―  Brake light (RH) terminal C—BCM terminal 2AB
―  High-mount brake light terminal B—BCM terminal 2AB
•  5HB:
―  Brake light (LH) terminal B—BCM terminal 2AB
―  Brake light (RH) terminal B—BCM terminal 2AB
―  High-mount brake light terminal A—BCM terminal 2AB
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 17.
No
Go to the next step.
9
INSPECT BRAKE LIGHT CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the high-mount brake light, brake light (LH), brake light (RH) and BCM connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the BCM terminal 2AB (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  4SD:
―  Brake light (LH) terminal C—BCM terminal 2AB
―  Brake light (RH) terminal C—BCM terminal 2AB
―  High-mount brake light terminal B—BCM terminal 2AB
•  5HB:
―  Brake light (LH) terminal B—BCM terminal 2AB
―  Brake light (RH) terminal B—BCM terminal 2AB
―  High-mount brake light terminal A—BCM terminal 2AB
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 17.
10
INSPECT BRAKE LIGHT CIRCUIT FOR OPEN CIRCUIT
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Verify that the high-mount brake light, brake light (LH), brake light (RH) and BCM connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  4SD:
•  Brake light (LH) terminal C—BCM terminal 2AB
•  Brake light (RH) terminal C—BCM terminal 2AB
•  High-mount brake light terminal B—BCM terminal 2AB
―  5HB:
•  Brake light (LH) terminal B—BCM terminal 2AB
•  Brake light (RH) terminal B—BCM terminal 2AB
•  High-mount brake light terminal A—BCM terminal 2AB
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  4SD:
―  Brake light (LH) terminal C—BCM terminal 2AB
―  Brake light (RH) terminal C—BCM terminal 2AB
―  High-mount brake light terminal B—BCM terminal 2AB
•  5HB:
―  Brake light (LH) terminal B—BCM terminal 2AB
―  Brake light (RH) terminal B—BCM terminal 2AB
―  High-mount brake light terminal A—BCM terminal 2AB
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 17.
11
INSPECT HIGH-MOUNT BRAKE LIGHT FOR SHORT TO GROUND
•  Verify that the high-mount brake light, brake light (LH), brake light (RH) and BCM connectors are disconnected.
•  Connect the high-mount brake light connector.
•  Inspect for continuity between BCM terminal 2AB (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Replace the high-mount brake light, then go to Step 17.
(See HIGH-MOUNT BRAKE LIGHT REMOVAL/INSTALLATION.)
No
Go to the next step.
12
INSPECT HIGH-MOUNT BRAKE LIGHT FOR SHORT TO POWER SUPPLY
•  Verify that the brake light (LH), brake light (RH) and BCM connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the BCM terminal 2AB (wiring harness-side).
•  Is the voltage 0 V?
Yes
With rear combination light (bulb type):
•  Go to Step 17.
With rear combination light (LED type):
•  Go to the next step.
No
Replace the high-mount brake light, then go to the next step.
(See HIGH-MOUNT BRAKE LIGHT REMOVAL/INSTALLATION.)
13
INSPECT BRAKE LIGHT (LH) FOR SHORT TO GROUND
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Verify that the brake light (LH), brake light (RH) and BCM connectors are disconnected.
•  Connect the brake light (LH) connector.
•  Inspect for continuity between BCM terminal 2AB (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Replace the rear combination light (LH), then go to Step 17.
(See REAR COMBINATION LIGHT REMOVAL/INSTALLATION.)
No
Go to the next step.
14
INSPECT BRAKE LIGHT (LH) FOR SHORT TO POWER SUPPLY
•  Verify that the brake light (RH) and BCM connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the BCM terminal 2AB (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Replace the rear combination light (LH), then go to Step 17.
(See REAR COMBINATION LIGHT REMOVAL/INSTALLATION.)
15
INSPECT BRAKE LIGHT (RH) FOR SHORT TO GROUND
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Verify that the brake light (RH) and BCM connectors are disconnected.
•  Connect the brake light (RH) connector.
•  Inspect for continuity between BCM terminal 2AB (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Replace the rear combination light (RH), then go to Step 17.
(See REAR COMBINATION LIGHT REMOVAL/INSTALLATION.)
No
Go to the next step.
16
INSPECT BRAKE LIGHT (RH) FOR SHORT TO POWER SUPPLY
•  Verify that BCM connector is disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the BCM terminal 2AB (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Replace the rear combination light (RH), then go to the next step.
(See REAR COMBINATION LIGHT REMOVAL/INSTALLATION.)
17
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Connect the negative battery cable.
•  Clear the DTC for the BCM using the M-MDS.
•  Depress the brake pedal.
•  Retrieve the BCM DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the BCM.
Go to the next step.
No
Go to the next step.
18
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.