Body Control Systems: Diagnosis Lexus GS II рестайлинг

CLEARING DIAGNOSTIC TROUBLE CODES

The DTC will be cleared when the trouble output to DTC is recovered normally.

CONFIRMATION TEST

After repairs have been completed, confirm that problem has been eliminated. Operate system under same conditions recorded for original complaint. If problem is no longer present and no DTCs are present, repair has corrected problem. If problem is still present or DTCs are reset, further diagnosis and repair is required.

Scheme 1

Scheme 2

Scheme 3

Circuit Description

During the warning of the anti-theft system, the body ECU No. 1 activates the anti-theft horn.

Inspection Procedure

For circuit wiring diagram (Scheme 4)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the anti-theft horn using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Connect the terminals Tc and E1 of DLC1 located in the driver side of the engine compartment near the engine room junction block No. 3. (Scheme 1) See «CONNECTOR IDENTIFICATION»(ref-152747-S09167790772003022400000). Check that the anti-theft horn sounds using ACTIVE TEST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the anti-theft horn. See «ANTI-THEFT HORN»(ref-153092-S36939158662003031400000) under COMPONENT TESTS under ANTI-THEFT SYSTEMS article in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the anti-theft horn.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the anti-theft horn and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 4

When the anti-theft system is preparing to set, the circuit lights up the indicator light. When the system has been set, it continually turns the indicator light on for one second and turns it off for one second, thus blinking the indicator light. This anti-theft indicator is connected to the Engine Control Module (ECM) and outputs the key judgment of the immobilizer system.

For circuit wiring diagram (Scheme 5)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the anti-theft indicator using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Connect the terminals Tc and E1 of DLC1 located in the driver side of the engine compartment near the engine room junction block No. 3. (Scheme 1) See «CONNECTOR IDENTIFICATION»(ref-152747-S09167790772003022400000). Check that the anti-theft indicator light can light in ACTIVE TEST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the anti-theft indicator. See «ANTI-THEFT INDICATOR LIGHT»(ref-153092-S30484968952003031400000) under COMPONENT TESTS under ANTI-THEFT SYSTEMS article in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the anti-theft indicator.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the anti-theft indicator and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 5

This switch is used to detect abnormality of the brake fluid level.

For circuit wiring diagram (Scheme 6)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the brake fluid level warning switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the brake fluid level warning switch using DATA LIST. See «BRAKE FLUID LEVEL WARNING SWITCH DATA LIST»(ref-152747-S34015127852003022500000) table. If the results are OK, inspect the instrument cluster. See «INSTRUMENT PANEL»(ref-153134) article. If the results are not OK, go to the next step. BRAKE FLUID LEVEL WARNING SWITCH DATA LIST Brake Fluid Level Switch Normal OFF Abnormal ON
2. Check the brake fluid level warning switch. See «BRAKE FLUID LEVEL WARNING SWITCH»(ref-153134-S17583095382003032000000) article under COMPONENT TESTS in INSTRUMENT PANEL article. If the results are OK, go to the next step. If the results are not OK, replace the brake fluid warning switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the brake fluid level warning switch and body ECU No. 2. If the results are OK, inspect the instrument cluster and replace as necessary. See «INSTRUMENT PANEL»(ref-153134) article. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 6

The body ECU No. 2 will send the light dim signal to the clock and dim the light.

For circuit wiring diagram (Scheme 7)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the clock using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the clock will dim it's light in ACTIVE TEST. If the clock dims it's light, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the clock does not dim it's light, go to the next step.
2. Check the clock. See «CLOCK»(ref-152747-S08996359562003022600000) under COMPONENT TESTS. If the results are OK, go to the next step. If the results are not OK, replace the clock.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the clock and body ECU No. 2. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 7

For circuit wiring diagram (Scheme 8)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the driver buckle switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the driver buckle switch using DATA LIST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, go to the next step.
2. Check the driver buckle switch. See «SEAT BELT BUCKLE SWITCH»(ref-153134-S13193235262003031900000) article under COMPONENT TESTS in INSTRUMENT PANEL. If the results are OK, go to the next step. If the results are not OK, replace the driver buckle switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the driver buckle switch and body ECU No. 2. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 8

The body ECU No. 2 receives the generator "L" signal from Engine Control Module (ECM) through communication and outputs it to the daytime running light relay. The daytime running light relay judges whether the engine rotates or not with this generator "L" signal and makes the daytime running light turn ON and OFF.

For circuit wiring diagram (Scheme 9)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the generator "L" terminal output using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the generator L terminal output using DATA LIST. See «GENERATOR L TERMINAL DATA LIST»(ref-152747-S41953511982003022600000) table. If the results are OK, inspect the parking brake switch. See «PARKING BRAKE SWITCH»(ref-153134-S11133616372003031900000) article under COMPONENT TESTS in INSTRUMENT PANEL. If the results are not OK, go to the next step. GENERATOR "L" TERMINAL DATA LIST Condition Generator "L" Terminal Engine Running ON Engine Not Running OFF
2. Check terminal E3-15 (RL) of the Engine Control Module (ECM). See «CONNECTOR IDENTIFICATION»(ref-152747-S09167790772003022400000). Check the voltage of terminal E3-15 (RL) of the Engine Control Module (ECM). See «CHECKING ECM TERMINAL E3-15 (RL) VOLTAGE»(ref-152747-S17419431812003022600000) table. If the voltage is OK, go to the next step. If the voltage is not OK, replace the body ECU No. 2. See «BODY ECU NO. 2»(ref-152690-S14036606732003022400000) under REMOVAL & INSTALLATION under MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES. CHECKING ECM TERMINAL E3-15 (RL) VOLTAGE Condition Voltage Engine Running 10-14 Volts Engine Not Running 0 Volt
3. Check for short to power, short to ground and continuity in the wiring harness and connector between Engine Control Module (ECM) and generator. If the results are OK, repair or replace the generator or regulator. See appropriate GENERATORS & REGULATORS article in ELECTRICAL. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 9

The body ECU No. 1 activates the flasher relay during the anti-theft system and flashes the hazard warning lights.

For circuit wiring diagram (Scheme 10)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the hazard warning lights operation using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the hazard warning lights can operate in an ACTIVE TEST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the hazard warning lights switch. See «HAZARD WARNING SWITCH»(ref-153134-S25778214312003032100000) article under COMPONENT TESTS in INSTRUMENT PANEL. If the results are OK, go to the next step. If the results are not OK, replace the hazard switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the hazard warning lights switch and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 10

The headlight relay will be ON by operating the headlight switch. The transistor which activates the taillight relay has 2 types

1. One activates directly by the headlight switch for fail safe operation.
2. Another activates by the body ECU No. 2.

The one that activates by body ECU No. 2 has 2 systems and prevents the headlight from turning off at the time of one system trouble in the automatic operation circuit.

For circuit wiring diagram (Scheme 11)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the headlight relay using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the headlight relay can operate in ACTIVE TEST. If the headlight relay is normal, the headlights come ON. In case that the headlight relay activates but the headlight will not come on, check the headlight circuit. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the headlight relay. See «RELAYS»(ref-152818-S01995837352003022700000) article under COMPONENT TESTS in STEERING COLUMN SWITCHES. If the results are OK, go to the next step. If the results are not OK, replace the headlight relay.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the headlight relay and the body ECU No. 2. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 11

For circuit wiring diagram (Scheme 12)

1. Check the heater main relay. See HEATER MAIN RELAY under COMPONENT TESTS in appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC. If the results are OK, go to the next step. If the results are not OK, replace the heater main relay.
2. Check for short to power, short to ground and continuity in the wiring harness and connector between the heater main relay and body ECU No. 1. If the results are OK, inspect the blower motor circuit. See BLOWER MOTOR under SYSTEM TESTS in appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 12

The hood courtesy switch is built into the engine hood lock assembly and goes on when the engine hood is opened and goes off when the engine hood is closed.

For circuit wiring diagram (Scheme 13)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the hood courtesy switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the hood courtesy switch using DATA LIST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the engine hood courtesy switch. See «ENGINE HOOD COURTESY SWITCH»(ref-153092-S12928570022003031400000) under COMPONENT TESTS under ANTI-THEFT SYSTEMS article in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the engine hood courtesy switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the engine hood courtesy switch and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 13

The horn is connected to the body ECU No. 1 and activated by the body ECU No. 1 during the warning of the anti-theft system.

For circuit wiring diagram (Scheme 14)

1. Check the horn. See «HORN»(ref-152747-S04314995202004040900000) under COMPONENT TESTS. If the results are OK, go to the next step. If the results are not OK, replace the horn.
2. Check for short to power, short to ground and continuity in the wiring harness and connector between the horn relay and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are OK, repair or replace the wiring harness or connector.

Scheme 14

Receiving the courtesy signal from either of the door ECUs, the body ECU No. 2 will make the interior light, ignition light and foot light come on.

For circuit wiring diagram (Scheme 15)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the interior light, ignition switch light and foot light using hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the illumination can light in ACTIVE TEST. All the illumination should light on. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, go to the next step.
2. Check the illumination lights. For ignition key illumination, see «STEERING COLUMN SWITCHES»(ref-152818) article. For interior illumination, see «AUTOMATIC HEADLIGHTS & LIGHTING»(ref-152890) article in HEADLIGHTS. If the results are OK, go to the next step. If the results are not OK, replace the failed light.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between each illumination light and body ECU No. 2. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 15

Circuit Inspection

The key unlock warning switch goes on when the ignition key is inserted in the key cylinder and goes off when the ignition key is removed. The body ECU No. 2 operates the key confinement prevention function while the key unlock warning switch is on.

For circuit wiring diagram (Scheme 16)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the key unlock warning switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the key unlock switch using DATA LIST. If the results are OK, go to the next step. If the results are not OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table.
2. Check the key unlock warning switch. See «KEY UNLOCK WARNING SWITCH»(ref-152818-S21713855122003022700000) article under COMPONENT TESTS in STEERING COLUMN SWITCHES. If the results are OK, go to the next step. If the results are not OK, replace the key unlock warning switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the key unlock warning switch and body ECU No. 2. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 16

The lamp failure sensor detects a wire break of the stop light, high mount stop light and taillight and sends that signal to the body ECU No. 2.

For circuit wiring diagram (Scheme 17)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the lamp failure sensor using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Remove either bulb of the stop light high mount stop light or taillight and check the operation of the lamp failure sensor with DATA LIST. See «LAMP FAILURE SENSOR DATA LIST»(ref-152747-S29043934732003022600000) table. If the results are OK, inspect the instrument cluster. See «INSTRUMENT PANEL»(ref-153134) article. If the results are not OK, go to the next step. LAMP FAILURE SENSOR DATA LIST Lamp Condition Lamp Failure Sensor (Tester Display) Normal OFF Lamp Wire Break (Or Removed) ON
2. Check for short to power, short to ground and continuity in the wiring harness and connector between the lamp failure sensor and body ECU No. 2. If the results are OK, inspect the instrument cluster. See «INSTRUMENT PANEL»(ref-153134) article. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 17

For circuit wiring diagram (Scheme 18)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the headlight control switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the headlight control switch using DATA LIST. (Scheme 19) If the results are not OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, go to the next step.
2. Check the headlight control switch. See «LIGHT CONTROL SWITCH»(ref-152818-S12423211872003022800000) article under COMPONENT TESTS in STEERING COLUMN SWITCHES. If the results are OK, go to the next step. If the results are not OK, replace the headlight control switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the headlight control switch and body ECU No. 2. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 18

Scheme 19

The luggage compartment door lock and unlock switch goes on when the luggage compartment door key cylinder is turned to the unlock side with the key.

For circuit wiring diagram (Scheme 20)

1. Check the luggage compartment door lock and unlock switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the luggage compartment door lock and unlock switch using DATA LIST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the luggage compartment door key lock and unlock switch. See «LUGGAGE COMPARTMENT DOOR KEY LOCK & UNLOCK SW»(ref-153092-S27650856462003031700000) under COMPONENT TESTS under ANTI-THEFT SYSTEMS article in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the luggage compartment door lock and unlock switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the luggage compartment door lock and unlock switch and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 20

The luggage compartment door courtesy switch goes on when the luggage compartment door is opened and goes off when the luggage compartment door is closed.

For circuit wiring diagram (Scheme 21)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the luggage compartment door courtesy switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the luggage compartment door courtesy switch using DATA LIST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the luggage compartment door courtesy switch. See «LUGGAGE COMPARTMENT DOOR COURTESY SWITCH»(ref-152890-S20065930872003030400000) under COMPONENT TESTS under AUTOMATIC HEADLIGHTS & LIGHTING article in HEADLIGHTS. If the results are OK, go to the next step. If the results are not OK, replace the luggage compartment door courtesy switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the luggage compartment door courtesy switch and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 21

For circuit wiring diagram (Scheme 21)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the luggage compartment door opener motor using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the luggage compartment door opener motor can operate in ACTIVE TEST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the luggage compartment door opener motor. See «LUGGAGE COMPARTMENT DOOR OPENER MOTOR»(ref-152941-S23267421872003030600000) under POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the luggage compartment door opener motor.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the luggage compartment door opener motor and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

For circuit wiring diagram (Scheme 22)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the luggage compartment door opener switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the luggage compartment door opener switch using DATA LIST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the luggage compartment door opener switch and main switch. See «LUGGAGE COMPARTMENT DOOR OPENER SWITCH & MAIN SWITCH»(ref-152941-S27844251262003030600000) article under COMPONENT TESTS under POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the luggage compartment door opener switch and main switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the luggage compartment door opener switch and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 22

This circuit detects the conditions of the mirror selection switch and the mirror position switch.

For circuit wiring diagram (Scheme 23)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the mirror switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the mirror switch using DATA LIST. If the results are OK, inspect the body ECU No. 2. If the results are not OK, go to the next step.
2. Check the mirror switch. See «POWER MIRROR SWITCH»(ref-153072-S40905350102003031200000) under COMPONENT TESTS under POWER MIRRORS article in MIRRORS. If the results are OK, go to the next step. If the results are not OK, replace the mirror switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the mirror switch and body ECU No. 2. If the results are OK, inspect the body ECU No. 2. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 23

For circuit wiring diagram (Scheme 24)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the parking brake switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the parking brake switch using DATA LIST. If the results are OK, inspect the body ECU No. 1. If the results are not OK, go to the next step.
2. Check the parking brake switch. See «PARKING BRAKE SWITCH»(ref-153134-S11133616372003031900000) article under COMPONENT TESTS in INSTRUMENT PANEL. If the results are OK, go to the next step. If the results are not OK, replace the parking brake switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between parking brake switch and body ECU No. 1. If the results are OK, inspect the brake fluid level warning switch. See «BRAKE FLUID LEVEL WARNING SWITCH CIRCUIT»(ref-152747-S41740988242003022500000). If the results are not OK, repair or replace the wiring harness or connector.

Scheme 24

The body ECU No. 1 detects the state of the pattern select switch.

For circuit wiring diagram (Scheme 25)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the pattern select switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the pattern select switch using DATA LIST. If the results are OK, inspect the Engine Control Module (ECM). Check Electronic Control Module (ECM) connector for loose, damaged or corroded terminals and repair as necessary. If connector is okay, check ECM ground circuits. See appropriate wiring diagram in POWER DISTRIBUTION in «WIRING DIAGRAMS»(ref-134952) article. Repair as necessary. If ground circuits are okay, replace ECM with a known-OK ECM and retest. If the results are not OK, go to the next step.
2. Check the pattern select switch. See «PATTERN SELECT SWITCH»(ref-140961-S08148052562002061000000) under COMPONENT TESTS under DIAGNOSIS - A-650E article under AUTOMATIC TRANSMISSION in TRANSAXLE/TRANSMISSION. If the results are OK, go to the next step. If the results are not OK, replace the pattern select switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the pattern select switch and body ECU No. 1. If the results are OK, inspect the Engine Control Module (ECM). If the results are not OK, repair or replace the wiring harness or connector.

Scheme 25

This circuit provides power to operate the body ECU No. 1.

For circuit wiring diagram (Scheme 26)

1. Check the continuity of the ECU-B2, RADIO No. 2, P FR DOOR and ECU-IG fuses. See «COMPONENT LOCATIONS»(ref-152747-S17717101232003022400000) table. If there is continuity, go to the next step. If there is not continuity, replace the failed fuse.
2. Check the voltage between terminals BECU, BSUB, IG and ACC and GND of the body ECU No. 1 connector. Turn the ignition switch OFF. Disconnect the body ECU No. 1 connector. Measure the voltage between terminals IG, ACC and GND. If voltage is between 10-14 volts, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the voltage is not as specified, go to the next step.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between body ECU No. 1 and body ground. If the results are OK, check and repair the wiring harness and connector between the body ECU No. 1 and battery. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 26

This circuit provides power to operate the body ECU No. 2.

For circuit wiring diagram (Scheme 27)

1. Check the continuity of the ECU-B2 and ECU-IG fuses. See «COMPONENT LOCATIONS»(ref-152747-S17717101232003022400000) table. If there is continuity, go to the next step. If there is not continuity, replace the failed fuse.
2. Turn the ignition switch ON. Measure the voltage between terminals IG and GND. Turn the ignition switch OFF. Disconnect the body ECU No. 2 connector. Measure the voltage between terminals BECU and GND. If the voltage is between 10-14 volts, perform the next test procedure of the problem symptom. See «BODY ECU NO. 2 PROBLEM SYMPTOM INDEX»(ref-152747-S35442773992003022500000) table. If the voltage is not as specified, go to the next step.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the body ECU No. 2 and body ground. If the results are OK, check and repair the wiring harness and connector between the body ECU No. 2 and battery.

Scheme 27

This circuit is the power source of the master switch for the driver's door and the door lock switch for the passenger's door.

For circuit wiring diagram (Scheme 28)

Check for short to power, short to ground and continuity in the wiring harness and connectors between the master switch and body ECU No. 1, and door lock switch of passenger door and body ECU No. 1. If the results are OK, inspect the power window master switch circuit. See POWER WINDOW MASTER SWITCH CIRCUIT (DRIVER) under CIRCUIT TESTS under POWER WINDOWS in WINDOWS. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 28

For circuit wiring diagram (Scheme 29)

1. Check the rear defogger relay. See «DEFOGGER RELAY»(ref-153173-S00942994472003032400000) under COMPONENT TESTS under REAR WINDOW DEFOGGER & HEATED MIRRORS article in HEATED GLASS/DEFOGGERS. If the results are OK, go to the next step. If the results are not OK, replace the rear defogger relay.
2. Check for short to power, short to ground and continuity in the wiring harness and connector between the rear defogger relay and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 29

The body ECU No. 2 detects the condition of the stop light switch.

For circuit wiring diagram (Scheme 30)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the stop light switch using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check the stop light switch using DATA LIST. If the results are OK, inspect the Engine Control Module (ECM) and stop light switch circuit. See «DTC P1520/52: SHORT IN STOP LIGHT SWITCH CIRCUIT»(ref-153091-S34936386072003032600000) article under DIAGNOSTIC TESTS under SELF-DIAGNOSTIC SYSTEM in CRUISE CONTROL SYSTEM. If the results are not OK, go to the next step.
2. Check the stop light switch. See «STOP LIGHT SWITCH»(ref-152747-S28916856382003022600000) under COMPONENT TESTS. If the results are OK, go to the next step. If the results are not OK, replace the stop light switch.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the stop light switch and body ECU No. 2. If the results are OK, inspect the Engine Control Module (ECM) and stop light switch circuit. See «DTC P1520/52: SHORT IN STOP LIGHT SWITCH CIRCUIT»(ref-153091-S34936386072003032600000) article under DIAGNOSTIC TESTS under SELF-DIAGNOSTIC SYSTEM in CRUISE CONTROL SYSTEM. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 30

The taillight relay will be ON by operating the taillight switch. The transistor which activates the taillight relay has 2 types

1. One activated by the taillight switch for fail safe operation.
2. Another activated by the body ECU No. 2.

For circuit wiring diagram (Scheme 31)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the taillight relay using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the taillight relay can operate in ACTIVE TEST. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, go to the next step.
2. Check the taillight relay. See «FOG LIGHT, HORN & TAILLIGHT CONTROL RELAY»(ref-152818-S16113479122003022800000) under RELAYS under COMPONENT TESTS in STEERING COLUMN SWITCHES. If the results are OK, go to the next step. If the results are not OK, replace the taillight relay.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the taillight relay and body ECU No. 2, battery and taillight relay. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 31

For circuit wiring diagram (Scheme 32)

Note. If using the hand-held tester, start the inspection from step 1 and if not using the hand-held tester, start from step 2 .

1. Check the wireless door lock buzzer using the hand-held tester. Connect the hand-held tester to DLC3. see scheme 6 Check that the wireless door lock buzzer can be operated in ACTIVE TEST. If the wireless buzzer sounds, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the wireless door lock buzzer does not sound, go to the next step.
2. Check the wireless door lock buzzer. See «WIRELESS DOOR LOCK BUZZER»(ref-153097-S20131500842003031700000) under COMPONENT TESTS under REMOTE KEYLESS ENTRY SYSTEMS article in DOOR LOCKS & ANTI-THEFT SYSTEMS. If the results are OK, go to the next step. If the results are not OK, replace the wireless door lock buzzer.
3. Check for short to power, short to ground and continuity in the wiring harness and connector between the wiring harness door lock buzzer and body ECU No. 1. If the results are OK, perform the next test procedure of the problem symptom. See «BODY ECU NO. 1 PROBLEM SYMPTOM INDEX»(ref-152747-S28174465832003022400000) table. If the results are not OK, repair or replace the wiring harness or connector.

Scheme 32

The pressure of the magnetic wave signals which are sent from the transmitter is checked in RSSI line. The RCO line is used to transmit the signals which control power supply of the transmitter.

For circuit wiring diagram (Scheme 33)

1. Check that DTC 42 is not output. If the result is OK, go to the next step. If the result is not OK, check the RDA line. See «DTC B1242/42: WIRELESS DOOR LOCK TUNER CIRCUIT»(ref-152690-S06472471252003022000000) under DIAGNOSTIC TESTS under MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES.
2. Check the wiring harness. Disconnect the connectors of the wireless door lock tuner and B5 of the body ECU No. 1. Check the continuity between terminals RCO of the wireless door lock tuner and RCO of the body ECU No. 1. If there is continuity, go to the next step. If there is not continuity, repair or replace the wiring harness.
3. Check the wireless door lock tuner. Replace the wireless door lock tuner with a known-good unit and check if system operates normally. If the wireless door lock tuner system operates normally, replace original wireless door lock tuner. If the results are not OK, reinstall original wireless door lock tuner and go to «KEY UNLOCK WARNING SWITCH CIRCUIT»(ref-152747-S17776050002003022400000) diagnosis.

Scheme 33