BODY NO. 1 ELECTRONIC CONTROL UNIT
The body No. 1 ECU has communication and control capabilities. The body No. 1 ECU processes data signals received from all ECUs and sends electrical load data signals to each ECU. The main function of the body No. 1 ECU is to control the anti-theft system and control the locking of the front and rear passenger doors and trunk.
BODY NO. 2 ELECTRONIC CONTROL UNIT
The body No. 2 ECU has communication and control capabilities. The body No. 2 ECU processes data signals received from all ECUs and sends electrical load data signals to each ECU. The main function of the body No. 2 ECU is to control the interior and exterior lights.
DRIVER'S DOOR ELECTRONIC CONTROL UNIT
The driver's door ECU is a slave unit of the body ECUs and has communication and control capabilities. The driver's door ECU uses data signals from body ECU to control on/off operation of electrical loads. The main function of the driver's door ECU is to control the driver's door power window and driver's door outside mirror (if equipped with driver's memory system).
FRONT PASSENGER'S DOOR ELECTRONIC CONTROL UNIT (ECU)
The front passenger's door ECU is a slave unit of the body ECUs and has communication and control capabilities. The front passenger's door ECU uses data signals from body ECU to control on/off operation of electrical loads. The main function of the front passenger's door ECU is to control front passenger door outside mirror (if equipped with driver's memory system).
POWER SEAT ELECTRONIC CONTROL UNIT (ECU)
The power seat ECU is a slave unit of the body ECU and has communication and control capabilities. The power seat ECU uses data signals from body ECUs to control on/off operation of electrical loads. The main function of the power seat ECU is to control the driver's memory system (if equipped).
DOOR COMMUNICATION BUS
If bus is shorted to battery voltage or ground, bus will be able to communicate using bus cut function. In bus cut function, the ECUs listed can still communicate
- Body No. 1 ECU
- Body No. 2 ECU
- A/C Control Assembly
- Multi-Display ECU (if equipped)
- Tilt & Telescopic ECU
- Instrument Panel ECU
- ECM
The following DTCs will be set: B1211, B1212, B1214 (short to battery voltage), B1215 (short to ground), B1216, B1217, B1272, B1273, and B1275. See SELF-DIAGNOSTICS.
INSTRUMENT PANEL COMMUNICATION BUS
If bus is shorted to battery voltage or ground, bus will be able to communicate using bus cut function. Body No. 1 ECU and door communication bus are cut off by bus cut relay. In bus cut function, the ECUs listed can still communicate
- Driver Door ECU
- Passenger Door ECU
- Left Rear Door ECU
- Right Rear Door ECU
- Seat ECU
- Sun Roof ECU
- Accessory Bus Buffer
The following DTCs will be set: B1211, B1212, B1213, B1216, B1217, B1218, B1261, B1262, B1266 (short to battery voltage), B1267 (short to ground), B1271, B1272, B1273, B1273 and B1275. See SELF-DIAGNOSTICS.
With Lexus Hand-Held Tester
Connect Lexus Hand-Held Tester (scan tool) to Data Link Connector (DLC 3), located under left side of instrument panel. Turn ignition on. Trouble codes are retrieved following tester instructions. Trouble codes are displayed on tester. All trouble codes are 4-digit numbers preceded by the letter "B".
Without Lexus Hand-Held Tester
Codes from multiplex self-diagnostic system are retrieved through Data Link Connector 1 (DLC1). With key on engine off, connect jumper wire between DLC1 terminal E1 and terminal Tc. (Scheme 15) Trouble codes are displayed as flashes of open door indicator light, located in instrument panel. All trouble codes are 2-digit numbers. Pay careful attention to length of pauses in order to read codes correctly. If any code is present, perform test(s) in order given. See MULTIPLEX TROUBLE CODE DEFINITION table.
Scheme 15
| Code No. (1) | Diagnosis Problem | Perform DTC Test No. |
|---|---|---|
| 11 | Body No. 1 ECU To Driver's Door ECU Communication | 1 |
| 12 | Body No. 1 ECU To Passenger's Door ECU Communication | 2 |
| 13 | Body No. 1 ECU To Tilt/Telescopic ECU Communication | 3 |
| 14 | Door System Communication Bus Shorted To Battery Voltage | 4 |
| 15 | Door System Communication Bus Shorted To Ground | 4 |
| 16 | Body No. 1 ECU To Right Rear Door ECU Communication | 5 |
| 17 | Body No. 1 ECU To Left Rear Door ECU Communication | 6 |
| 18 | Body No. 2 ECU Communication | 7 |
| 21 | Power Window Master Switch Circuit | 8 |
| 22 | Driver's Key Lock & Unlock Switch Circuit | 8 |
| 23 | Passenger's Power Window Switch Circuit | 8 |
| 24 | Passenger's Key Lock & Unlock Switch Circuit | 8 |
| 25 | Right Rear Door Power Window Switch Circuit | 8 |
| 26 | Left Rear Door Power Window Switch Circuit | 8 |
| 31 | Driver's Door Jam Limit Switch Circuit | 9 |
| 32 | Driver's Door Pulse Limit Switch Circuit | 10 |
| 33 | Passenger's Door Jam Limit Switch Circuit | 9 |
| 34 | Passenger's Door Pulse Limit Switch Circuit | 10 |
| 35 | Right Rear Door Jam Limit Switch Circuit | 9 |
| 36 | Right Rear Door Pulse Limit Switch Circuit | 10 |
| 37 | Left Rear Door Jam Limit Switch Circuit | 9 |
| 38 | Left Rear Door Pulse Limit Switch Circuit | 10 |
| 41 | Body No. 1 ECU Switch Circuit (Trunk) | 8 |
| 42 | Remote Keyless Entry Circuit | 11 |
| 43 | GSW Terminal Circuit | 12 |
| 44 | Light Sensor Circuit | 13 |
| 52 | Body No. 2 ECU Switch Circuit (Stoplight) | 8 |
| 53 | Body No. 2 ECU GSW Terminal (Low) | 12 |
| 54 | Body No. 2 ECU GSW Terminal (High) | 12 |
| 55 | Body No. 2 ECU P1 Switch | 14 |
| 61 | Body No. 1 ECU To ECM Communication | 15 |
| 62 | Body No. 1 ECU To A/C ECU Communication | 16 |
| 66 | Instrument Panel Communication Bus Shorted To Battery Voltage | 17 |
| 67 | Instrument Panel Communication Bus Shorted To Ground | 17 |
| 71 | Instrument Panel ECU Communication | 18 |
| 72 | Power Seat ECU Communication | 19 |
| 73 | Sun Roof ECU Communication | 20 |
| 75 | Accessory Bus Buffer Communication | (2) |
| (1) Codes are listed as 2 digit (without Lexus Hand-Held Tester). For tester codes, codes are preceded by B12. (2) Check wiring harness of affected accessory. | ||
| (1) | Codes are listed as 2 digit (without Lexus Hand-Held Tester). For tester codes, codes are preceded by B12. |
| (2) | Check wiring harness of affected accessory. |
MULTIPLEX TROUBLE CODE DEFINITION