DTC U0231:68 [FRONT BODY CONTROL MODULE (FBCM)]

id0902p2010300

Description

Communication error with auto light sensor/rain sensor

Detection condition

•  Front body control module (FBCM) could not receive the signals from the auto light sensor/rain sensor for 5 s or more with the ignition switched ON (engine off or on).

Fail-safe function

Not applicable

Possible cause

•  Auto light sensor/rain sensor connector or terminal malfunction

•  Front body control module (FBCM) connector or terminal malfunction

•  Short to ground in wiring harness between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G

•  Short to power supply in wiring harness between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G

•  Open circuit in wiring harness between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G

•  Auto light sensor/rain sensor malfunction

•  Front body control module (FBCM) malfunction

Description	Communication error with auto light sensor/rain sensor
Detection condition	• Front body control module (FBCM) could not receive the signals from the auto light sensor/rain sensor for 5 s or more with the ignition switched ON (engine off or on).
Fail-safe function	Not applicable
Possible cause	• Auto light sensor/rain sensor connector or terminal malfunction • Front body control module (FBCM) connector or terminal malfunction • Short to ground in wiring harness between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G • Short to power supply in wiring harness between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G • Open circuit in wiring harness between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G • Auto light sensor/rain sensor malfunction • Front body control module (FBCM) malfunction

Diagnostic Procedure

Step	Inspection		Action
1	VERIFY FRONT BODY CONTROL MODULE (FBCM) DTCs AGAIN • Clear the DTC for the front body control module (FBCM) using the M-MDS. (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].) • Switch the ignition ON (engine off or on) and wait for 5 s or more. • Retrieve the front body control module (FBCM) DTCs using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Is the same DTC displayed?	Yes	Go to the next step.
1		No	Go to Step 9.
2	INSPECT AUTO LIGHT SENSOR/RAIN SENSOR CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) • Disconnect the auto light sensor/rain sensor 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.
2		No	Repair or replace the connector, then go to Step 8.
3	INSPECT FRONT BODY CONTROL MODULE (FBCM) CONNECTOR CONDITION • Disconnect the front body control module (FBCM) 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.
3		No	Repair or replace the connector, then go to Step 8.
4	INSPECT FOR SHORT TO GROUND IN AUTO LIGHT SENSOR/RAIN SENSOR CIRCUIT • Verify that the auto light sensor/rain sensor and front body control module (FBCM) connectors are disconnected. • Inspect for continuity between front body control module (FBCM) terminal 2G (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 auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G. 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 8.
4		No	Go to the next step.
5	INSPECT FOR SHORT TO POWER SUPPLY IN AUTO LIGHT SENSOR/RAIN SENSOR CIRCUIT • Verify that the auto light sensor/rain sensor and front body control module (FBCM) connectors are disconnected. • Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) • Switch the ignition ON (engine off or on). • Measure the voltage at the front body control module (FBCM) terminal 2G (wiring harness-side). • Is the voltage 0 V?	Yes	Go to the next step.
5		No	Refer to the wiring diagram and verify whether or not there is a common connector between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G. 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 8.
6	INSPECT FOR OPEN CIRCUIT IN AUTO LIGHT SENSOR/RAIN SENSOR CIRCUIT • Verify that the auto light sensor/rain sensor and front body control module (FBCM) connectors are disconnected. • Switch the ignition off. • Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) • Inspect the wiring harness for continuity between auto light sensor/rain sensor terminal A (wiring harness-side) and front body control module (FBCM) terminal 2G (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
6		No	Refer to the wiring diagram and verify whether or not there is a common connector between auto light sensor/rain sensor terminal A and front body control module (FBCM) terminal 2G. 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 8.
7	PERFORM DTC INSPECTION AND VERIFY AUTO LIGHT SENSOR/RAIN SENSOR MALFUNCTION • Always reconnect all disconnected connectors. • Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) • Clear the DTC for the front body control module (FBCM) using the M-MDS. (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].) • Switch the ignition ON (engine off or on) and wait for 5 s or more. • Retrieve the front body control module (FBCM) DTCs using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Is the same DTC displayed?	Yes	Replace the auto light sensor/rain sensor, then go to the next step. (See RAIN SENSOR REMOVAL/INSTALLATION.)
7		No	Go to Step 9.
8	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Always reconnect all disconnected connectors. • Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) • Clear the DTC for the front body control module (FBCM) using the M-MDS. (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].) • Switch the ignition ON (engine off or on) and wait for 5 s or more. • Retrieve the front body control module (FBCM) DTCs using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the front body control module (FBCM). (See FRONT BODY CONTROL MODULE (FBCM) REMOVAL/INSTALLATION.) Go to the next step.
8		No	Go to the next step.
9	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 [FRONT BODY CONTROL MODULE (FBCM)].)
9		No	DTC troubleshooting completed.