Body Control System: Other Lexus GS II

POWER WINDOW MASTER SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check For DTC B1221 Using scan tool, check for DTC B1221. If DTC B1221 is retrieved, go to next step. If DTC B1221 is not retrieved, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Power Window Master Switch Check power window master switch. See POWER WINDOWS article. If switch is okay, go to next step. Replace switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between power window master switch and driver door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

PASSENGER DOOR LOCK CONTROL SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check For DTC B1224 Using scan tool, check for DTC B1224. If DTC B1224 is retrieved, go to next step. If DTC B1224 is not retrieved, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Passenger Door Lock Control Switch Check passenger door lock control switch. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If switch is okay, go to next step. Replace switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between passenger door lock control switch and passenger door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next step.
4. Check Red/Yellow Wire Check for faults in Red/Yellow wire between passenger door lock control switch and power window master switch. See WIRING DIAGRAMS. Repair or replace as necessary. If wire is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

DRIVER DOOR KEY LOCK & UNLOCK SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check For DTC B1222 Using scan tool, check for DTC B1222. If DTC B1222 is retrieved, go to next step. If DTC B1222 is not retrieved, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Driver Door Key Lock & Unlock Switch Check driver door key lock and unlock switch. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If switch is okay, go to next step. Replace switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between driver door key lock and unlock switch and driver door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

PASSENGER DOOR KEY LOCK & UNLOCK SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check For DTC B1224 Using scan tool, check for DTC B1224. If DTC B1224 is retrieved, go to next step. If DTC B1224 is not retrieved, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Passenger Door Key Lock & Unlock Switch Check passenger door key lock and unlock switch. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If switch is okay, go to next step. Replace switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between passenger door key lock and unlock switch and passenger door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

KEY UNLOCK WARNING SWITCH CIRCUIT

1. Check Key Unlock Warning Switch Check key unlock warning switch. See STEERING COLUMN SWITCHES article. If switch is okay, go to next step. Replace switch as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between key unlock warning switch and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

DRIVER DOOR LOCK MOTOR CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Door Lock Motor Using Scan Tool Using scan tool, attempt to operate driver door lock motor in ACTIVE TEST. If door lock motor does not operate in ACTIVE TEST, go to next step. If door lock motor operates properly in ACTIVE TEST, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Door Lock Motor Check driver door lock motor. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If door lock motor is okay, go to next step. Replace door lock motor as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between driver door lock motor and driver door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

PASSENGER DOOR LOCK MOTOR CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Door Lock Motor Using Scan Tool Using scan tool, attempt to operate passenger door lock motor in ACTIVE TEST. If door lock motor does not operate in ACTIVE TEST, go to next step. If door lock motor operates properly in ACTIVE TEST, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Door Lock Motor Check passenger door lock motor. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If door lock motor is okay, go to next step. Replace door lock motor as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between passenger door lock motor and passenger door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LEFT REAR DOOR LOCK MOTOR CIRCUIT

1. Check Door Lock Motor Check left rear door lock motor. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If door lock motor is okay, go to next step. Replace door lock motor as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between left rear door lock motor and left rear door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

RIGHT REAR DOOR LOCK MOTOR CIRCUIT

1. Check Door Lock Motor Check right rear door lock motor. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If door lock motor is okay, go to next step. Replace door lock motor as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between right rear door lock motor and right rear door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LUGGAGE COMPARTMENT DOOR OPENER SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Luggage Compartment Opener Switch Using Scan Tool Using scan tool, check luggage compartment opener switch using DATA LIST. If luggage compartment opener switch is not okay, go to next step. If luggage compartment opener switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Luggage Compartment Main Switch & Opener Switch Check luggage compartment main switch and opener switch. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If switch is okay, go to next step. Replace luggage compartment switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between luggage compartment opener switch and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LUGGAGE COMPARTMENT DOOR OPENER MOTOR CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Luggage Compartment Opener Motor Using Scan Tool Using scan tool, operate luggage compartment opener motor in ACTIVE TEST. If luggage compartment opener motor does not operate, go to next step. If luggage compartment opener motor operates properly, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Luggage Compartment Opener Motor Check luggage compartment opener motor. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. If motor is okay, go to next step. Replace luggage compartment opener motor as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between luggage compartment opener motor and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

WIRELESS DOOR LOCK TUNER CIRCUIT

1. Check For DTC 42 Using Scan Tool Using scan tool, check for DTC 42. If DTC 42 is not retrieved, go to next step. If DTC 42 is retrieved, check for faults in Pink wire between wireless door lock tuner and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary.
2. Check Circuits Check circuits for open between wireless door lock tuner and body control ECU No. 1. If circuits are okay, go to next step. Repair or replace circuits as necessary.
3. Check Wireless Door Lock Tuner Replace original wireless door lock tuner with known-good unit and ensure it recovers normally. If it recovers normally, original wireless door lock tuner failed. If it does not recover normally, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

DRIVER DOOR UNLOCK DETECTION SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Door Unlock Detection Switch Using Scan Tool Using scan tool, check driver door unlock detection switch using DATA LIST. If door unlock detection switch is not okay, go to next step. If door unlock detection switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Door Unlock Detection Switch Check driver door unlock detection switch. See DOOR UNLOCK DETECTION SWITCH under COMPONENT TESTS. If switch is okay, go to next step. Replace door unlock detection switch (motor assembly) as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between driver door unlock detection switch and driver door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

PASSENGER DOOR UNLOCK DETECTION SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Door Unlock Detection Switch Using Scan Tool Using scan tool, check passenger door unlock detection switch using DATA LIST. If door unlock detection switch is not okay, go to next step. If door unlock detection switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Door Unlock Detection Switch Check passenger door unlock detection switch. See DOOR UNLOCK DETECTION SWITCH under COMPONENT TESTS. If switch is okay, go to next step. Replace door unlock detection switch (motor assembly) as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between passenger door unlock detection switch and passenger door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LEFT REAR DOOR UNLOCK DETECTION SWITCH CIRCUIT

1. Check Door Unlock Detection Switch Check left rear door unlock detection switch. See DOOR UNLOCK DETECTION SWITCH under COMPONENT TESTS. If switch is okay, go to next step. Replace door unlock detection switch (motor assembly) as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between left rear door unlock detection switch and left rear door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

RIGHT REAR DOOR UNLOCK DETECTION SWITCH CIRCUIT

1. Check Door Unlock Detection Switch Check right rear door unlock detection switch. See DOOR UNLOCK DETECTION SWITCH under COMPONENT TESTS. If switch is okay, go to next step. Replace door unlock detection switch (motor assembly) as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between right rear door unlock detection switch and right rear door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

DRIVER DOOR COURTESY LIGHT & COURTESY SWITCH CIRCUIT

1. Check Driver Door Courtesy Light Operation Open and close driver door while observing driver door courtesy light operation. If driver door courtesy light does not illuminate when door is opened and go out when door is closed, go to next step. If driver door courtesy light operates as specified, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Driver Door Courtesy Light Check driver door courtesy light. See DOOR COURTESY LIGHT under COMPONENT TESTS. If driver door courtesy light is okay, go to next step. Replace driver door courtesy light as necessary. Retest system operation.
3. Check Driver Door Courtesy Switch Check driver door courtesy switch. See DOOR COURTESY SWITCH under COMPONENT TESTS. If driver door courtesy switch is okay, go to next step. Replace driver door courtesy switch as necessary. Retest system operation.
4. Check Circuits Check circuits for faults between driver door courtesy light, driver door courtesy switch and driver door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

PASSENGER DOOR COURTESY LIGHT & COURTESY SWITCH CIRCUIT

1. Check Passenger Door Courtesy Light Operation Open and close passenger door while observing passenger door courtesy light operation. If passenger door courtesy light does not illuminate when door is opened and go out when door is closed, go to next step. If passenger door courtesy light operates as specified, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Passenger Door Courtesy Light Check passenger door courtesy light. See DOOR COURTESY LIGHT under COMPONENT TESTS. If passenger door courtesy light is okay, go to next step. Replace passenger door courtesy light as necessary. Retest system operation.
3. Check Passenger Door Courtesy Switch Check passenger door courtesy switch. See DOOR COURTESY SWITCH under COMPONENT TESTS. If passenger door courtesy switch is okay, go to next step. Replace passenger door courtesy switch as necessary. Retest system operation.
4. Check Circuits Check circuits for faults between passenger door courtesy light, passenger door courtesy switch and passenger door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LEFT REAR DOOR COURTESY LIGHT & COURTESY SWITCH CIRCUIT

1. Check Left Rear Door Courtesy Light Operation Open and close left rear door while observing left rear door courtesy light operation. If left rear door courtesy light does not illuminate when door is opened and go out when door is closed, go to next step. If left rear door courtesy light operates as specified, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Left Rear Door Courtesy Light Check left rear door courtesy light. See DOOR COURTESY LIGHT under COMPONENT TESTS. If left rear door courtesy light is okay, go to next step. Replace left rear door courtesy light as necessary. Retest system operation.
3. Check Left Rear Door Courtesy Switch Check left rear door courtesy switch. See DOOR COURTESY SWITCH under COMPONENT TESTS. If left rear door courtesy switch is okay, go to next step. Replace left rear door courtesy switch as necessary. Retest system operation.
4. Check Circuits Check circuits for faults between left rear door courtesy light, left rear door courtesy switch and left rear door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

RIGHT REAR DOOR COURTESY LIGHT & COURTESY SWITCH CIRCUIT

1. Check Right Rear Door Courtesy Light Operation Open and close right rear door while observing right rear door courtesy light operation. If right rear door courtesy light does not illuminate when door is opened and go out when door is closed, go to next step. If right rear door courtesy light operates as specified, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Right Rear Door Courtesy Light Check right rear door courtesy light. See DOOR COURTESY LIGHT under COMPONENT TESTS. If right rear door courtesy light is okay, go to next step. Replace right rear door courtesy light as necessary. Retest system operation.
3. Check Right Rear Door Courtesy Switch Check right rear door courtesy switch. See DOOR COURTESY SWITCH under COMPONENT TESTS. If right rear door courtesy switch is okay, go to next step. Replace right rear door courtesy switch as necessary. Retest system operation.
4. Check Circuits Check circuits for faults between right rear door courtesy light, right rear door courtesy switch and right rear door ECU. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

WIRELESS DOOR LOCK BUZZER CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Wireless Door Lock Buzzer Using Scan Tool Using scan tool, operate wireless door lock buzzer in ACTIVE TEST. If wireless door lock buzzer does not operate, go to next step. If wireless door lock buzzer operates, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Wireless Door Lock Buzzer Check wireless door lock buzzer. See WIRELESS DOOR LOCK BUZZER under COMPONENT TESTS. If buzzer is okay, go to next step. Replace wireless door lock buzzer as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between wireless door lock buzzer and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

ANTI-THEFT INDICATOR CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Anti-Theft Indicator Using Scan Tool Connect a jumper wire between DLC1 connector terminals E1 and Tc. (Scheme 1) Using scan tool, operate anti-theft indicator in ACTIVE TEST. If anti-theft indicator does not operate, go to next step. If anti-theft indicator operates, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Anti-Theft Indicator Check anti-theft indicator. See ANTI-THEFT INDICATOR under COMPONENT TESTS. If anti-theft indicator is okay, go to next step. Replace anti-theft indicator as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between anti-theft indicator, body control ECU No. 1 and ground. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

Scheme 1

ENGINE HOOD COURTESY SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Engine Hood Courtesy Switch Using Scan Tool Using scan tool, check engine hood courtesy switch using DATA LIST. If engine hood courtesy switch is not okay, go to next step. If engine hood courtesy switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Engine Hood Courtesy Switch Check engine hood courtesy switch. See ENGINE HOOD COURTESY SWITCH under COMPONENT TESTS. If switch is okay, go to next step. Replace engine hood courtesy switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between engine hood courtesy switch and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LUGGAGE COMPARTMENT DOOR COURTESY SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Luggage Compartment Door Courtesy Switch Using Scan Tool Using scan tool, check luggage compartment door courtesy switch using DATA LIST. If luggage compartment door courtesy switch is not okay, go to next step. If luggage compartment door courtesy switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Luggage Compartment Door Courtesy Switch Check luggage compartment door courtesy switch. See DOOR COURTESY SWITCH under COMPONENT TESTS. If switch is okay, go to next step. Replace luggage compartment door courtesy switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between luggage compartment door courtesy switch and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

HEADLIGHT RELAY CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Headlight Relay Using Scan Tool Using scan tool, operate headlight relay in ACTIVE TEST. If headlight relay does not operate (headlights do not illuminate), go to next step. If headlight relay operates (headlights illuminate), go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Headlight Relay Check headlight relay. See HEADLIGHT RELAY under COMPONENT TESTS. If headlight relay is okay, go to next step. Replace headlight relay as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between headlight relay, body control ECU No. 2 and battery. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

TAILLIGHT RELAY CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Taillight Relay Using Scan Tool Using scan tool, operate taillight relay in ACTIVE TEST. If taillight relay does not operate (taillights do not operate), go to next step. If taillight relay operates (taillights operate), go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Taillight Relay Check taillight relay. See TAILLIGHT RELAY under COMPONENT TESTS. If taillight relay is okay, go to next step. Replace taillight relay as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between taillight relay, body control ECU No. 2 and battery. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

HAZARD SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Hazard Switch Using Scan Tool Using scan tool, operate hazard switch in ACTIVE TEST. If hazard switch does not operate (hazard lights do not operate), go to next step. If taillight relay operates (taillights operate), go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Hazard Switch Check hazard switch. See HAZARD SWITCH under COMPONENT TESTS. If hazard switch is okay, go to next step. Replace hazard switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between hazard switch and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

ANTI-THEFT HORN CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Anti-Theft Horn Using Scan Tool Connect a jumper wire between DLC1 connector terminals E1 and Tc. (Scheme 1) Using scan tool, operate anti-theft horn in ACTIVE TEST. If anti-theft horn does not operate, go to next step. If anti-theft horn operates, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Anti-Theft Horn Check anti-theft horn. See ANTI-THEFT HORN under COMPONENT TESTS. If anti-theft horn is okay, go to next step. Replace anti-theft horn as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between anti-theft horn and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

STANDARD HORN CIRCUIT

1. Check Standard Horn Check standard horn. See STANDARD HORN under COMPONENT TESTS. If standard horn is okay, go to next step. Replace standard horn as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between horn relay, body control ECU No. 1 and battery. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

STOPLIGHT SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Stoplight Switch Using Scan Tool Using scan tool, check stoplight switch using DATA LIST. If stoplight switch is not okay, go to next step. If stoplight switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Stoplight Switch Check stoplight switch. See STOPLIGHT SWITCH under COMPONENT TESTS. If stoplight switch is okay, go to next step. Replace stoplight switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between stoplight switch, body control ECU No. 2 and battery. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

SHIFT LOCK SOLENOID CIRCUIT

1. Check Shift Lock Solenoid Check shift lock solenoid. See SHIFT LOCK SOLENOID under COMPONENT TESTS. If shift lock solenoid is okay, go to next step. Replace shift lock solenoid as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between shift lock solenoid and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

LIGHT SENSOR CIRCUIT

Note. LEXUS scan tool must be used for this test.

1. Check Light Sensor Using scan tool, check light sensor output frequency. If light sensor frequency output is 47-1200 Hertz, go to next step. If light sensor frequency output is not 47-1200 Hertz, replace light sensor and retest system operation.
2. Check Circuits Check circuits for faults between light sensor and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, check body control ECU No. 2 pin voltages. See PIN VOLTAGES. Replace as necessary and retest system operation.

HEADLIGHT CONTROL SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Headlight Control Switch Using Scan Tool Using scan tool, check headlight control switch using DATA LIST. If headlight switch is not okay, go to next step. If headlight switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Headlight Control Switch Check headlight control switch. See STEERING COLUMN SWITCHES article. If headlight control switch is okay, go to next step. Replace headlight control switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between headlight control switch and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

ILLUMINATION CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Light Failure Sensor Using Scan Tool Remove high mounted stoplight or taillight. Using scan tool, check light failure sensor using DATA LIST. If light failure sensor is not okay, go to next step. If light failure sensor is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check circuits for faults between light failure sensor and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

DRIVER SEAT BELT BUCKLE SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Driver Seat Belt Buckle Switch Using Scan Tool Using scan tool, check driver seat belt buckle switch using DATA LIST. If driver seat belt buckle switch is not okay, go to next step. If driver seat belt buckle switch is okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Driver Seat Belt Buckle Switch Check driver seat belt buckle switch. See DRIVER SEAT BELT BUCKLE SWITCH under COMPONENT TESTS. If driver seat belt buckle switch is okay, go to next step. Replace driver seat belt buckle switch as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between driver seat belt buckle switch and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

PASSENGER SEAT BELT BUCKLE SWITCH CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Passenger Seat Belt Buckle Switch & Warning Occupant Detection Sensor Using Scan Tool Using scan tool, check passenger seat belt buckle switch and warning occupant detection sensor using DATA LIST. If passenger seat belt buckle switch and warning occupant detection sensor are not okay, go to next step. If passenger seat belt buckle switch and warning occupant detection sensor are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Passenger Seat Belt Buckle Switch Check passenger seat belt buckle switch. See PASSENGER SEAT BELT BUCKLE SWITCH under COMPONENT TESTS. If passenger seat belt buckle switch is okay, go to next step. Replace passenger seat belt buckle switch as necessary. Retest system operation.
3. Check Warning Occupant Detection Sensor Check warning occupant detection sensor. See WARNING OCCUPANT DETECTION SENSOR under COMPONENT TESTS. If warning occupant detection sensor is okay, go to next step. Replace warning occupant detection sensor as necessary. Retest system operation.
4. Check Circuits Check circuits for faults between passenger seat belt buckle switch, warning occupant detection sensor, body control ECU No. 2 and ground. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

CLOCK CIRCUIT

Note. If LEXUS scan tool is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Check Clock Using Scan Tool Using scan tool, check clock light dimming in ACTIVE TEST. If clock light does not dim, go to next step. If clock light dims, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
2. Check Clock Check clock. See CLOCK under COMPONENT TESTS. If clock is okay, go to next step. Replace clock as necessary. Retest system operation.
3. Check Circuits Check circuits for faults between clock, body control ECU No. 2 and battery. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

DEFOGGER RELAY CIRCUIT

1. Check Rear Defogger Relay Check rear defogger relay. See REAR WINDOW & SIDE MIRROR DEFOGGERS article. If rear defogger relay is okay, go to next step. Replace rear defogger relay as necessary. Retest system operation.
2. Check Circuits Check circuits for faults between rear defogger relay and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.

POWER SOURCE CIRCUIT NO. 1

Note. Body control ECU No. 1 is plugged into passenger-side junction block. To check voltages, it is necessary to probe wiring going into junction block. (Scheme 3)

1. Check Fuses Check condition of MPX-B, RADIO No. 2, DOOR and GAUGE fuse. See FUSE LOCATIONS table. If fuses are okay, go to next step. If fuse(s) are not okay, replace appropriate fuse and retest system operation.
2. Check For Voltage Ensure ignition is off. Disconnect body control ECU No. 1 connector (located behind front passenger right side kick panel). Using a voltmeter, check voltage between ECU No. 1 connector terminal No. 15 and White/Black wire (GND) leading into junction block. (Scheme 2)and (Scheme 3). Check voltage between Black/Red wire (IG) and White/Black wire (GND) leading into junction block. Check voltage between White wire (BSUB) and White/Black wire (GND) leading into junction block. Check voltage between Green/White wire (BECU) and White/Black wire (GND) leading into junction block. If voltages are not 10-14 volts, go to next step. If voltages are 10-14 volts, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
3. Check Circuits Check circuits for faults between ground and body control ECU No. 1. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, check and repair circuits between body control ECU No. 1 and battery. Retest system operation.

FUSE LOCATIONS

Scheme 2

Scheme 3

POWER SOURCE CIRCUIT NO. 2

Note. Body control ECU No. 2 is plugged into driver-side junction block. To check voltages, it is necessary to probe wiring going into junction block. (Scheme 4)

1. Check Fuses Check condition of MPX-B and GAUGE fuse. See FUSE LOCATIONS table. If fuses are okay, go to next step. If fuse(s) are not okay, replace appropriate fuse and retest system operation.
2. Check For Voltage Turn ignition on. Using a voltmeter, check voltage between Black/Yellow wire (IG) and White/Black wire (GND) leading into junction block. (Scheme 4) Check voltage between Green/White wire (BECU) and White/Black wire (GND) leading into junction block. If voltages are not 10-14 volts, go to next step. If voltages are 10-14 volts, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
3. Check Circuits Check circuits for faults between ground and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, check and repair circuits between body control ECU No. 2 and battery. Retest system operation.

Scheme 4

ANTI-THEFT HORN

Disconnect anti-theft horn connector (located on right side of engine compartment, on fenderwell). Connect battery positive lead to terminal No. 1 (Pink/Black wire) and negative battery lead to horn body. If horn does not operate, replace horn. If horn operates, repair or replace wire harness and connectors between anti-theft horn and body control ECU No. 1.

ANTI-THEFT INDICATOR

Disconnect indicator light 7-pin connector. Connect battery positive lead to terminal No. 2 (Violet wire) and negative battery lead to terminal No. 5 (White/Black wire). (Scheme 5) If indicator light does not come on, replace light and retest system operation. If indicator light comes on, repair or replace wire harness and connectors between indicator light, body ECU No. 1 and combination meter (instrument cluster).

Scheme 5

CLOCK

Disconnect clock 8-pin connector. Using a voltmeter, check voltage between ground and clock 8-pin connector terminal No. 4 (Blue/Yellow wire). Battery voltage should exist. Check voltage between ground and clock 8-pin connector terminal No. 5 (Gray wire). Battery voltage should exist. Check voltage between ground and clock 8-pin connector terminal No. 1 (White/Black wire). Battery voltage should not exist. If voltages are as specified, replace clock and retest system operation. If voltages are not as specified, repair or replace wire harness and retest system operation.

DOOR COURTESY LIGHT

Remove door courtesy light. Using an ohmmeter, check continuity between courtesy light bulb terminals. Continuity should exist. If continuity does not exist, replace courtesy light bulb and retest system operation.

DOOR COURTESY SWITCH

Remove door courtesy switch. Using an ohmmeter, check continuity between courtesy switch terminals. Continuity should exist with switch pin released. Continuity should not exist with switch pin pressed. If continuity is not as specified, replace courtesy switch and retest system operation.

Front Doors

1. Remove door trim panel and service hole cover. Disconnect electrical connector from door lock motor. Connect ohmmeter between the following terminals (component side of connector). Left front door motor; terminals No. 3 (Brown/Black wire) and No. 4 (Gray wire). Right front door motor; terminals No. 3 (Green wire) and No. 4 (Brown/Black wire).
2. When door is locked, there should be no continuity. When door is unlocked, there should be continuity. If continuity is not as specified, replace door unlock detection switch and retest system operation.

Rear Doors

1. Remove door trim panel and service hole cover. Disconnect electrical connector from door lock motor. Connect ohmmeter between the following terminals (component side of connector). Left rear door motor; terminals No. 3 (Green wire) and No. 4 (Brown/Black wire). Right rear door motor; terminals No. 1 (Brown/Black wire) and No. 2 (Green wire).
2. When door is locked, there should be no continuity. When door is unlocked, there should be continuity. If continuity is not as specified, replace door unlock detection switch and retest system operation.

DRIVER SEAT BELT BUCKLE SWITCH

Check for continuity between buckle switch 4-pin connector (component side) terminals No. 2 (Black/Blue wire) and No. 3 (White/Black wire) with belt fastened. Continuity should exist. Check for continuity between buckle switch connector terminals No. 2 and No. 3 with belt unfastened. Continuity should not exist. If continuity is not as specified, replace seat belt buckle.

ENGINE HOOD COURTESY SWITCH

Remove engine hood courtesy switch. Using an ohmmeter, check continuity between engine hood courtesy switch terminals. Continuity should exist with switch pin released. Continuity should not exist with switch pin pressed. If continuity is not as specified, replace courtesy switch and retest system operation.

HAZARD SWITCH

Remove hazard switch. With switch in OFF position, there should be continuity between switch terminals No. 7 and 10. (Scheme 6) With switch in ON position, there should be continuity between terminals No. 7 and 8, and between terminals No. 4, 5, 6 and 9. With switch in either position, there should be continuity between terminals No. 2 and 3 (illumination light). If continuity is not as specified, replace switch.

Scheme 6

HEADLIGHT RELAY

Remove headlight relay (located in relay block No. 1, on right side of engine compartment behind shock tower). Using an ohmmeter, check continuity between relay terminals. Continuity should exist between terminals No. 1 and 2. (Scheme 7) Continuity should not exist between terminals No. 3 and 4. Apply battery voltage and ground between terminals No. 1 and 2. Continuity should exist between terminals No. 3 and 4.

Scheme 7

PASSENGER SEAT BELT BUCKLE SWITCH

Check for continuity between buckle switch 4-pin connector (component side) terminals No. 2 (Black/Orange wire) and No. 3 (White/Black wire) with belt fastened. Continuity should exist. Check for continuity between buckle switch connector terminals No. 2 and No. 3 with belt unfastened. Continuity should not exist. If continuity is not as specified, replace seat belt buckle.

SHIFT LOCK SOLENOID

Disconnect shift lock solenoid connector (located at ignition switch). Using an ohmmeter, check resistance between solenoid connector terminal No. 3 and 4. (Scheme 8) Resistance should be 12-17 ohms. While touching solenoid, connect battery positive lead to terminal No. 3 and negative battery lead to terminal No. 4. Solenoid operation should be felt. If resistance or operation is not as specified, replace solenoid and retest system operation.

Scheme 8

STANDARD HORN

Disconnect standard horn connector (located behind center of grill and behind right-side of front bumper). Connect battery positive lead to terminal No. 1 (Black wire) and negative battery lead to horn body. If horn does not operate, replace horn. If horn operates, repair or replace wire harness and connectors between horn and horn relay.

STOPLIGHT SWITCH

Disconnect stoplight switch connector (located on brake pedal support). Check continuity between stoplight switch terminals. With brake pedal pressed, continuity should exist between terminals No. 1 and 2, and continuity should not exist between terminals No. 3 and 4. (Scheme 9) With brake pedal released, continuity should exist between terminals No. 3 and 4, and continuity should not exist between terminals No. 1 and 2. If continuity is not as specified, replace stoplight switch and retest system operation.

Scheme 9

TAILLIGHT RELAY

Remove taillight relay (located in driver-side junction block, behind left kick panel). Using an ohmmeter, check continuity between relay terminals. Continuity should not exist between terminals No. 3 and 5. (Scheme 10) Apply battery voltage and ground between terminals No. 1 and 2. Continuity should exist between terminals No. 3 and 5.

Scheme 10

WARNING OCCUPANT DETECTION SENSOR

Disconnect passenger seat belt warning occupant detection sensor 2-pin connector (located under passenger seat). Using an ohmmeter, check resistance between sensor connector terminals. Continuity should exist while pressing on sensor. Continuity should not exist while not pressing sensor. If continuity is not as specified, replace warning occupant detection sensor and retest system operation.

WIRELESS DOOR LOCK BUZZER

Disconnect wireless door lock buzzer connector (located behind left kick panel). Using an ohmmeter, check resistance between wireless door lock buzzer terminals. Resistance should be one k/ohm. If resistance is not as specified, replace wireless door lock buzzer and retest system operation.

PIN VOLTAGE TESTS

Note. Perform this procedure only if you already performed the appropriate test (see TROUBLE SHOOTING or CIRCUIT TESTS) and the system still does not operate properly.

BODY CONTROL ECU NO. 1 CONNECTOR

Measure voltage by backprobing between following body control ECU No. 1 terminals. (Scheme 11) If voltages are not as specified, repair wire harness or replace components as necessary. If voltages are as specified, body control ECU No. 1 may be faulty. Body control ECU No. 1 uses connector B5.

B5-1 & Ground

With anti-theft system set and luggage compartment door key lock and unlock switch off and luggage compartment door closed, voltage should be 10-14 volts.

With anti-theft system set, luggage compartment door key lock and unlock switch off and luggage compartment door opened, voltage should be less than one volt.

B5-2 & Ground

With luggage compartment door opener switch on, voltage should be 10-14 volts.

B5-9 & Ground

With engine hood opened, voltage should be less than one volt. With engine hood closed, voltage should be 10-14 volts.

B5-10 & Ground

With luggage compartment door opened, voltage should be less than one volt. With luggage compartment door closed, voltage should be 10-14 volts.

B5-12 & B5-13

With buzzer sounding, voltage should be 8-10 volts. With buzzer not sounding, voltage should be less than one volt.

B5-15 & Ground

With ignition switch in ACC position, voltage should be 10-14 volts.

B5-16 & Ground

With luggage compartment door key lock and unlock switch turned, voltage should be less than one volt. With luggage compartment door key lock and unlock switch not turned, voltage should be 10-14 volts.

B5-17 & Ground

With luggage compartment door opener switch actuated, voltage should be less than one volt. With luggage compartment door opener switch not actuated, voltage should be 10-14 volts.

B5-18 & Ground

With passenger in passenger seat not wearing seat belt, voltage should be less than one volt. With passenger in passenger seat wearing seat belt, voltage should be 10-14 volts.

B5-22 & Ground

With anti-theft indicator illuminated, voltage should be 3-6 volts. Without anti-theft indicator illuminated, voltage should be less than one volt.

B5-23 & Ground

With transaxle PWR switch on, voltage should be less than one volt. With transaxle PWR switch off, voltage should be 10-14 volts.

B5-24 & Ground

With transaxle SNOW switch on, voltage should be less than one volt. With transaxle SNOW switch off, voltage should be 10-14 volts.

Scheme 11

BODY CONTROL ECU NO. 2 CONNECTOR

Measure voltage by backprobing between following body control ECU No. 1 terminals. (Scheme 11) If voltages are not as specified, repair wire harness or replace components as necessary. If voltages are as specified, body control ECU No. 2 may be faulty. Body control ECU No. 2 uses connector B6.

B6-1 & Ground

Under normal conditions, voltage should be 2-3.5 volts. With open circuit in wire harness, voltage should be less than one volt.

B6-2 & Ground

With headlight switch in TAIL position, voltage should be less than one volt. With headlight switch in any position except TAIL, voltage should be 10-14 volts.

B6-3 & Ground

With headlight switch in AUTO position, voltage should be less than one volt. With headlight switch in any position except AUTO, voltage should be 10-14 volts.

B6-4 & Ground

With stoplights and taillights operating normally, voltage should be 10-14 volts. With stoplights and taillights not operating properly, voltage should be less than one volt.

B6-5 & Ground

With key in ignition switch, voltage should be less than one volt. With key removed from ignition switch, voltage should be 10-14 volts.

B6-6 & Ground

With ignition in ON position and headlight control switch in HEAD position, voltage should be less than 2 volts. With ignition in ON position and headlight control switch off, voltage should be 10-14 volts.

B6-13 & Ground

With each door opened, voltage should be less than 2 volts. With all doors closed, voltage should be 10-14 volts.

B6-14 & Ground

With brake pedal pressed, voltage should be less than one volt. Without brake pedal pressed, voltage should be 10-14 volts.

B6-15 & Ground

With headlight switch in HEAD position, voltage should be less than one volt. With headlight switch in any position except HEAD, voltage should be 10-14 volts.

B6-18 & Ground

Under normal conditions, voltage should be 2-3.5 volts. With open circuit in wire harness, voltage should be 4-6 volts.

B6-20 & Ground

With transaxle gearshift selector in PARK position, voltage should be less than one volt. With transaxle gearshift selector in any position except PARK, voltage should be 10-14 volts.