Body Ecu No. 1 Control System Operation Check

NOTE: Prior to trouble shooting body control system, check multiplex communication system for proper operation and stored codes. The body control ECU's store Diagnostic Trouble Codes (DTCs) for the multiplex communication system and is the access point to communicate with other ECUs on the multiplex communication bus (circuit). See MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES.

Trouble shooting of a body ECU No. 1 control system complaint begins with verification of the customer problem. If problem occurs, go to step 3. If problem does not occur, go to next step.
If problem does not occur, review conditions under which problem occurred for customer and try to duplicate those conditions. For example, if the problem occurs on rainy days or during high humidity conditions, sprinkle water onto vehicle and see if malfunction occurs. DO NOT sprinkle water directly into engine compartment or onto electronic components. Visually inspect for signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harness and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary.
Inspect the multiplex communication system and confirm that there is no trouble by the basic inspection and DTC check. See PRE-CHECK under SELF-DIAGNOSTIC SYSTEM under MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES.

Determine problem symptom. See BODY ECU NO. 1 PROBLEM SYMPTOM INDEX table.

BODY ECU NO. 1 PROBLEM SYMPTOM INDEX

Symptom

Suspected Area ⁽¹⁾

Anti-Theft System

No Alerting Condition Is Operated (System Cannot Be Set)

⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽⁷⁾⁽⁸⁾⁽⁹⁾⁽¹⁰⁾

Cannot Be Canceled When IG Is ON With Key

⁽³⁾⁽¹¹⁾⁽⁹⁾⁽¹⁰⁾

Cannot Be Canceled When Unlocking Luggage Compartment Door With Key

⁽⁷⁾⁽¹⁰⁾

Some Of The System Does Not Operate (Headlight Does Not Light Up)

⁽¹²⁾⁽⁹⁾⁽¹⁰⁾

Some Of The System Does Not Operate (Taillight Does Not Light Up)

⁽¹³⁾⁽⁹⁾⁽¹⁰⁾

Some Of The System Does Not Operate (Hazard Does Not Light Up)

⁽¹⁴⁾⁽¹⁰⁾

Anti-Theft Horn Or Horn Does Not Sound

⁽¹⁵⁾⁽¹⁶⁾⁽¹⁰⁾

During Warning Condition, Cannot Be Canceled By Unlocking Door With Key

⁽¹⁷⁾⁽¹⁸⁾⁽¹⁰⁾

During Warning Condition, Cannot Be Canceled By Unlocking The Door With Key (Transmitter)

⁽¹⁹⁾⁽²⁰⁾⁽¹⁰⁾

During Warning Condition, Cannot Be Canceled By Turning ACC Or ON With Key

⁽¹¹⁾⁽³⁾⁽⁹⁾⁽¹⁰⁾

System Operated For More Than 60 Records

⁽¹⁰⁾

Door Lock Control

Lock Or Unlock Cannot Be Operated With Door Lock Control Switch

⁽²¹⁾⁽¹⁸⁾⁽¹⁰⁾

Door Key Linked Function Does Not Operate

⁽¹⁷⁾⁽¹⁸⁾⁽¹⁰⁾

Key Confinement Prevention Function Does Not Operate

⁽³⁾⁽⁹⁾⁽¹⁰⁾

Does Not Lock & Unlock Each Door Only

⁽²²⁾⁽⁸⁾

Luggage Compartment Door Opener Function Does Not Operate

⁽²³⁾⁽²⁴⁾⁽¹⁰⁾

Wireless Door Lock Control

All Functions Of Wireless Door Lock System Do Not Operate

⁽¹⁹⁾⁽²⁰⁾⁽³⁾⁽⁹⁾⁽¹⁰⁾

Lock (Or Unlock) Function Does Not Operate

⁽¹⁷⁾⁽⁵⁾⁽⁸⁾⁽¹⁰⁾

Automatic Lock Function Operates Even If Any Door Is Opened Within 30 Seconds After All Doors Are Unlocked By Wireless Door Lock Control System

⁽⁴⁾⁽⁸⁾⁽¹⁰⁾

Wireless Door Lock Operates, But Buzzer Does Not Sound

⁽²⁸⁾⁽¹⁰⁾

Buzzer Sounds, But Wireless Door Lock Function Does Not Operate

⁽¹⁰⁾

Luggage Compartment Door Opener

⁽²⁴⁾⁽¹⁰⁾

Other

Does Not Run Off Passenger Seat Belt Warning Light

⁽¹⁰⁾

Rear Window Defogger Does Not Operate

⁽²⁵⁾⁽²⁶⁾⁽¹⁰⁾

Body ECU No. 1 Does Not Operate

⁽²⁷⁾⁽¹⁰⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the anti-theft indicator circuit. See ANTI-THEFT INDICATOR CIRCUIT under CIRCUIT TESTS.

⁽³⁾	Check the key unlock warning switch circuit. See KEY UNLOCK WARNING SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁴⁾	Check the courtesy switch circuit. See AUTOMATIC HEADLIGHTS & LIGHTING article in HEADLIGHTS.

⁽⁵⁾	Check the door unlock detection switch circuit. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽⁶⁾	Check the engine hood courtesy switch circuit. See HOOD COURTESY SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁷⁾	Check the luggage room courtesy switch circuit. See LUGGAGE COURTESY SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁸⁾	Check any door ECU. See COMPONENT TESTS under POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article in DOOR LOCKS & ANTI-THEFT SYSTEMS.

⁽⁹⁾	Check the body ECU No. 2. See PRE-CHECK under SELF-DIAGNOSTIC SYSTEM under MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES.

⁽¹⁰⁾	Check the body ECU No. 1. See PRE-CHECK under SELF-DIAGNOSTIC SYSTEM under MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES.

⁽¹¹⁾	Check the ignition switch circuit. See STEERING COLUMN SWITCHES article.

⁽¹²⁾	Check the headlight relay circuit. See HEADLIGHT RELAY CIRCUIT under CIRCUIT TESTS.

⁽¹³⁾	Check the taillight relay circuit. See TAILLIGHT RELAY CIRCUIT under CIRCUIT TESTS.

⁽¹⁴⁾	Check the hazard switch circuit. See HAZARD SWITCH CIRCUIT under CIRCUIT TESTS.

⁽¹⁵⁾	Check the anti-theft horn circuit. See ANTI-THEFT HORN CIRCUIT under CIRCUIT TESTS.

⁽¹⁶⁾	Check the horn circuit. See HORN CIRCUIT under CIRCUIT TESTS.

⁽¹⁷⁾	Check the door key lock and unlock switch circuit. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article in DOOR LOCKS & ANTI-THEFT SYSTEMS.

⁽¹⁸⁾	Check the driver door ECU or passenger door ECU. See COMPONENT TESTS under POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article in DOOR LOCKS & ANTI-THEFT SYSTEMS.

⁽¹⁹⁾	Check the transmitter. See REMOTE KEYLESS ENTRY SYSTEMS article in DOOR LOCKS & ANTI-THEFT SYSTEMS.

⁽²⁰⁾	Check the wireless tuner circuit. See WIRELESS DOOR LOCK TUNER CIRCUIT under CIRCUIT TESTS.

⁽²¹⁾	Check the door lock control switch circuit (driver or passenger). See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article in DOOR LOCKS & ANTI-THEFT SYSTEMS.

⁽²²⁾	Check the door lock motor circuit. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article in DOOR LOCKS & ANTI-THEFT SYSTEMS.

⁽²³⁾	Check the luggage compartment door opener switch circuit. See LUGGAGE OPENER SWITCH CIRCUIT under CIRCUIT TESTS.

⁽²⁴⁾	Check the luggage compartment door opener motor circuit. See LUGGAGE OPENER MOTOR CIRCUIT under CIRCUIT TESTS.

⁽²⁵⁾	Check the rear defogger relay circuit. See REAR DEFOGGER RELAY CIRCUIT under CIRCUIT TESTS.

⁽²⁶⁾	Check the defogger switch and circuit. See DEFOGGER SWITCH CIRCUIT article under CIRCUIT TESTS under REAR WINDOW DEFOGGER & HEATED MIRRORS under HEATED GLASS/DEFOGGERS in ACCESSORIES & EQUIPMENT

⁽²⁷⁾	Check the power source circuit. See POWER SOURCE CIRCUIT (BODY ECU NO. 1) under CIRCUIT TESTS.

⁽²⁸⁾	Check the wireless door lock buzzer circuit. See WIRELESS DOOR LOCK BUZZER CIRCUIT under CIRCUIT TESTS.

Inspect the circuits of the body ECU No. 1. See CIRCUIT TESTS .
After problem has been identified and repaired, confirm repairs. See CONFIRMATION TEST under SELF-DIAGNOSTIC SYSTEM.