Multiplex Communication System: Diagnosis Lexus GS II рестайлинг

TROUBLE SHOOTING

1. Trouble shooting of a multiplex communication 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.
2. 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 harnesses 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. If problem still cannot be created, go to next step.
3. Perform pre-check. See «PRE-CHECK»(ref-152690-S01351968492003021900000) under SELF-DIAGNOSTIC SYSTEM. If a normal code is retrieved, go to the next step. If a malfunction code is retrieved, perform a circuit inspection. See «DIAGNOSTIC TROUBLE CODE INDEX»(ref-152690-S04339663422003021900000) table.
4. Determine the problem system. On GS 300 Model (Engine 2JZ-GE). See «SELF-DIAGNOSTICS - GS300»(ref-134937) article in ENGINE PERFORMANCE. On GS 430 Model (Engine 3UZ-FE). See «SELF-DIAGNOSTICS - GS430»(ref-134938) article in ENGINE PERFORMANCE. Body No. 1 ECU Control System. See «BODY CONTROL SYSTEMS»(ref-152747) article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. Body No. 2 ECU Control System. See «BODY CONTROL SYSTEMS»(ref-152747) article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. Driver Door System. See the appropriate article for the affected area (power door locks, power windows or power mirrors) of the driver door system. Passenger Door System. See the appropriate article for the affected area (power door locks, power windows or power mirrors) of the passenger door system. Rear Right Door System. See the appropriate article for the affected area (power door locks or power windows) of the rear right door system. Rear Left Door System. See the appropriate article for the affected area (power door locks or power windows) of the rear left door system. Air Conditioning System. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC. Power Tilt and Power Telescopic Steering Column. See appropriate POWER TILT & POWER TELESCOPIC STEERING COLUMN article in STEERING. Instrument Panel System. See «INSTRUMENT PANEL»(ref-153134) article in ACCESSORIES & EQUIPMENT. Moon Roof System. See «POWER MOON ROOF»(ref-153247) article under SUN ROOF/T-TOP/CONVERTIBLE TOP in ACCESSORIES & EQUIPMENT. Power Seat System. See «POWER & HEATED SEATS»(ref-153185) article under SEATS in ACCESSORIES & EQUIPMENT. LEXUS Navigation System. Further diagnosis information is not available.
5. Retrieve DTCs using the OPEN DOOR indicator light. See «USING OPEN DOOR INDICATOR LIGHT»(ref-152690-S04907618012003022000000) under RETRIEVING DIAGNOSTIC TROUBLE CODES.
6. Retrieve DTCs using the hand-held tester. See «USING HAND-HELD TESTER»(ref-152690-S17776252722003022000000) under RETRIEVING DIAGNOSTIC TROUBLE CODES.
7. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-152690-S14074035972003021900000) .
8. After problem has been identified and repaired, confirm repairs. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

CLEARING DIAGNOSTIC TROUBLE CODES

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

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TROUBLE CODE INDEX

Scheme 2

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.

Circuit Description

This DTC is output when communication stops between the driver door ECU and body ECU No. 1. (Scheme 3) There is no communication from the driver door ECU for more than 10 seconds.

Trouble Area

1. Wiring Harness.
2. Driver Door ECU.

Scheme 3

Diagnostic Procedure

1. Check the driver door ECU by checking if the driver door window glass operates when AUTO UP switch is pressed. With this inspection, the driver door ECU can be diagnosed if it works normally or not. If the results are OK, go to the next step. If the results are not good, replace the driver door ECU. See «DRIVER DOOR ECU & FRONT PASSENGER DOOR ECU»(ref-152690-S20587935902003021900000) under REMOVAL & INSTALLATION.
2. Check the wiring harness by disconnecting the connector of the body ECU No. 2, D24 of the driver door ECU and R12 of the rear left door ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the body ECU No. 2 and MPX1 of the driver door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX2 of the driver door ECU and MPX1 of the rear left door ECU. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If there is continuity in the wiring harness of both steps (A) and (B), or either (A) or (B), replace the driver door ECU. See «DRIVER DOOR ECU & FRONT PASSENGER DOOR ECU»(ref-152690-S20587935902003021900000) under REMOVAL & INSTALLATION. If there is not continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communication stops between the front passenger door ECU and body ECU No. 1. (Scheme 3) There is no communication from the front passenger door ECU more than 10 seconds.

Trouble Area

1. Wiring Harness.
2. Passenger Door ECU.

1. Check the front passenger door ECU by checking if the front passenger door window glass operates when AUTO UP switch is pressed. With this inspection, the front passenger door ECU can be diagnosed if it works normally or not. If the results are OK, go to the next step. If the results are not good, replace the front passenger door ECU. See «DRIVER DOOR ECU & FRONT PASSENGER DOOR ECU»(ref-152690-S20587935902003021900000) under REMOVAL & INSTALLATION.
2. Check the wiring harness by disconnecting the connector of body ECU No. 1, F11 of the front passenger door ECU and R13 of the rear right door ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check continuity between terminals MPX2 of body ECU No. 1 and MPX2 of the front passenger door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX1 of the passenger door ECU and MPX2 of the rear right door ECU. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If there is continuity in the wiring harness of both steps (A) and (B) or (A), or either (A) or (B), replace the front passenger door ECU. See «DRIVER DOOR ECU & FRONT PASSENGER DOOR ECU»(ref-152690-S20587935902003021900000) under REMOVAL & INSTALLATION. If there is not continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communication stops between the tilt and telescopic ECU and body ECU No. 1. (Scheme 4) There is no communication from the tilt and telescopic ECU more than 10 seconds.

Trouble Area

1. Wiring Harness.
2. Tilt and Telescopic ECU.

Scheme 4

1. Check the tilt and telescopic ECU by checking the operation of the manual tilt and telescopic. With this inspection, the tilt and telescopic ECU can be diagnosed if it works normally or not. If the results are OK, go to the next step. If the results are not good, replace the tilt and telescopic ECU. See appropriate POWER TILT & TELESCOPIC STEERING COLUMN article in STEERING.
2. Check the wiring harness by disconnecting the connector C8 of the air bag sensor assembly, T5 of the tilt and telescopic ECU, C16 of the steering pad switch, G6 of the gateway ECU and A13 of the A/C control assembly. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the air bag sensor assembly and MPX2 of the tilt and telescopic ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX1 of the tilt and telescopic ECU and MPD1, MPD2 of the gateway ECU. Check the continuity between terminals MPX1 of the tilt and telescopic ECU and MPX- of the A/C amplifier On GS 430 model only, check the continuity between terminals MPX1 of the steering pad switch and MPX2 of the tilt and telescopic ECU. If there is an OPEN in the wiring harness of either step (A), (B), (C) or (D), repair it. If continuity exists in the wiring harness, replace the tilt and telescopic ECU. See appropriate POWER TILT & TELESCOPIC STEERING COLUMN article in STEERING. If there is not continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when +B (battery voltage) or GND short occurs on the door system communication bus. If a +B or GND short is detected on the door system communication bus, separate it by bus cut relay in the body ECU No. 1 and body ECU No. 2 to prevent while communication buses' failure. see scheme 3

Trouble Area

1. Wiring Harness.
2. ECU (Door System Bus).

1. Check the communication circuit inside the driver door ECU by disconnecting the D24 connector of the driver door ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the DTC. The results are OK if DTC B1214/14 or B1215/15 are not output. If the results are OK, replace the driver door ECU. See «DRIVER DOOR ECU & FRONT PASSENGER DOOR ECU»(ref-152690-S20587935902003021900000) under REMOVAL & INSTALLATION. If the results are not good, go to the next step.
2. Check the communication circuit inside the rear left door ECU by connecting the D24 connector of the driver door ECU and disconnecting the R12 connector of the rear left door ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, replace the rear left door ECU. See «POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE»(ref-152941) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT. If the results are not good on a vehicle with driving position memory seat, go to the next step. If the results are not good on a vehicle without driving position memory seat, go to step 4 .
3. Check the communication circuit inside the power seat ECU by connecting the connector R12 of the rear left door ECU and disconnecting the connector P19 of the power seat ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, replace the power seat ECU. See «POWER & HEATED SEATS»(ref-153185) article under SEATS in ACCESSORIES & EQUIPMENT. If the results are not good, go to the next step.
4. Check the communication circuit inside the rear right door ECU by connecting the connector P19 of the power seat ECU and disconnecting the connector R13 of the rear right door ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, replace the rear right door ECU. See «POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE»(ref-152941) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT. If the results are not good, go to the next step.
5. Check the communication circuit inside the front passenger door ECU by connecting the connector R13 of the rear right door ECU and disconnecting the connector F11 of the front passenger door ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, replace the passenger door ECU. See «DRIVER DOOR ECU & FRONT PASSENGER DOOR ECU»(ref-152690-S20587935902003021900000) under REMOVAL & INSTALLATION. If the results are not good, go to the next step.
6. Check for short circuit between front passenger door ECU and rear right door ECU by disconnecting the connector R13 of the rear right door ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, repair or replace the wiring harness between the front passenger door ECU and rear right door ECU. If the results are not good on vehicles with driving position memory seat, go to the next step. If the results are not good on vehicles without driving position memory seat, go to step 8 .
7. Check for a short circuit between the rear right door ECU and the power seat ECU by connecting the F11 connector of the passenger door ECU and disconnecting the P19 connector of the power seat ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, repair or replace the wiring harness between the rear right door ECU and power seat ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
8. Check for a short circuit between the power seat ECU and the rear left door ECU by connecting the R13 connector of the rear right door ECU and disconnecting the R12 connector of the rear left door ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, repair or replace the wiring harness between the power seat ECU and the rear left door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
9. Check for a short circuit between the rear left door ECU and the driver door ECU by connecting the P19 connector of the power seat ECU and disconnecting the D24 connector of the driver door ECU. Check the DTC. The results are OK if DTC B1214/14 or B1215/15 is not output. If the results are OK, repair or replace the wiring harness between the rear left door ECU and the driver door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
10. Check for a short circuit between the driver door ECU and body ECU No. 2 by connecting the R12 connector of the rear left door ECU and disconnecting the connector of the body ECU No. 2. The connector is disconnected by removing the body ECU No. 2 from the driver side junction block. Check the DTC. The results are OK if DTC B1214/14 or DTC 1215/15 is not output. If the results are OK, repair or replace the wiring harness between the driver door ECU and the body ECU No. 2. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
11. Check for a short circuit between the passenger door ECU, moon roof ECU and body ECU No. 1 by connecting the D24 connector of the driver door ECU. Install the body ECU No. 2 to the driver side junction block. Disconnect the connector of the moon roof ECU and F11 of the passenger door ECU. Disconnect the connector of the body ECU No. 1. The connector is disconnected by removing the body ECU No. 1 from the passenger side junction block. Check the wiring harness between the passenger door ECU, moon roof ECU and body ECU No. 1. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are OK, repair or replace the wiring harness between the passenger door ECU, moon roof ECU and body ECU No. 1. If the results are not good, replace the body ECU No. 1. See «BODY ECU NO. 1»(ref-152690-S23433460862003021900000) under REMOVAL & INSTALLATION.
12. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communication stops between the rear right door ECU and the body ECU No. 1. (Scheme 3) There is no communication from the rear right door ECU for more than 10 seconds.

Trouble Area

1. Wiring Harness.
2. Right Rear Door ECU.

1. Check the rear right door ECU by checking if the rear right door window glass operates when AUTO UP switch is pressed. With this inspection, the rear right door ECU can be diagnosed if it works normal or not. If the results are OK, go to the next step. If the results are not good, replace the rear right door ECU. See «POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE»(ref-152941) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.
2. Check the wiring harness by disconnecting the F11 connector of the passenger door ECU, R13 of the rear right door ECU and P19 of the power seat ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the passenger door ECU and MPX2 of the rear right door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . On vehicles with driving position memory seat, check the continuity between terminals MPX1 of the rear right door ECU and MPX2 of the power seat ECU. On vehicles without the driving position memory seat, check the continuity between the terminals MPX1 of the rear right door ECU and MPX2 of the rear left door ECU. If there is an OPEN in the wiring harness of either step (A), (B) or (C), repair it. If there is continuity in the wiring harness of both steps (A) and (B), or either (A) or (B), replace the rear right door ECU. See «POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE»(ref-152941) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT. If the results are not good, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communication stops between the rear left door ECU and body ECU No. 1. (Scheme 3) There is no communication from the rear left door ECU for more than 10 seconds.

Trouble Area

1. Wiring Harness.
2. Rear Left Door ECU.

1. Check the rear left door ECU by checking if the rear left door window glass operates when AUTO UP switch is pressed. With this inspection, the rear left door ECU can be diagnosed if it works normal or not. If the results are OK, go to the next step. If the results are not good, replace the rear left door ECU. See «POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE»(ref-152941) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.
2. Check the wiring harness by disconnecting the D24 connector of the driver door ECU, R12 of the rear left door ECU and P19 of the power seat ECU (or on vehicles without driving position memory seat, R13 of the rear right door ECU). See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX2 of the driver door ECU and MPX1 of the rear left door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . On vehicles with driving position memory seat, check the continuity between terminals MPX2 of the rear left door ECU and MPX1 of the power seat ECU. On vehicles without the driving position memory seat, check the continuity between the terminals MPX2 of the rear left door ECU and MPX1 of the rear right door ECU. If there is an OPEN in the wiring harness of either step (A), (B) or (C), repair it. If there is continuity in the wiring harness of both steps (A) and (B) or (A) and (C), (A) or either (B) or (C), replace the rear left door ECU. See «POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE»(ref-152941) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT. If the results are not good, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communication stops between body ECU No. 2 and body ECU No. 1. (Scheme 3)and (Scheme 4). There is no communication from body ECU No. 2 for more than 10 seconds.

Trouble Area

1. Wiring Harness.
2. Body ECU No. 2.

1. Check the body ECU No. 2 by checking that the headlight comes on when operating the light control switch with the ignition switch off. With this inspection, the rear left door ECU can be diagnosed if it works normal or not. If the results are OK, go to the next step. If the results are not good, replace the body ECU No. 2. See «BODY ECU NO. 2»(ref-152690-S14036606732003022400000) under REMOVAL & INSTALLATION.
2. Check the wiring harness by disconnecting the connector of the body ECU No. 2, D24 of the driver door ECU and C12 of the instrument panel ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Remove the body ECU No. 2 from the driver side junction block. Check the continuity between terminals MPX1 of the body ECU No. 2 and MPX1 of the driver door ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX2 of the body ECU No. 2 and MPX- of the instrument panel ECU. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If there is continuity in the wiring harness of both steps (A) and (B), or either (A) or (B), replace the body ECU No. 2. See «BODY ECU NO. 2»(ref-152690-S14036606732003022400000) under REMOVAL & INSTALLATION. If the results are not good, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

When something wrong is found by this diagnosis, inspect each switch. See IDENTIFYING DTC B1221/21-26, B1241 & B1252/52 CONDITION table. If there is a problem, replace the switch. If there is no problem, check the wiring harness. See WIRING DIAGRAMS .

IDENTIFYING DTC B1221/21-26, B1241 & B1252/52 CONDITION

Note. No diagnostic procedure was provided by the manufacturer.

Note. No diagnostic procedure was provided by the manufacturer.

This DTC is output when the GND short of the RDA terminal is detected. (Scheme 5)

Trouble Area

1. Wiring Harness.
2. Wireless Door Lock Tuner.
3. Body ECU No. 1.

Scheme 5

1. Check the wiring harness by disconnecting the wireless door lock tuner and body ECU No. 1. (Scheme 6) Check the continuity between the wiring harness and body ground. If there is continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000). If there is not continuity, go to the next step.
2. Check the body ECU No. 1 by connecting the connector the body ECU No. 1. Check the DTC. If B1242/42 is output, replace the body ECU No. 1. See «BODY ECU NO. 1»(ref-152690-S23433460862003021900000) under REMOVAL & INSTALLATION. If B1242/42 is not output, replace the wireless door lock tuner. See «REMOTE KEYLESS ENTRY SYSTEMS»(ref-153097) article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 6

This DTC is output when failure of the light sensor circuit is detected. (Scheme 7) There is a malfunction of the light sensor or an open or short of the light sensor circuit.

Trouble Area

1. Light Sensor.
2. Wiring Harness.
3. Body ECU No. 2.

Scheme 7

1. Check the light sensor by connecting the hand-held tester to the DLC3. Turn the ignition switch ON and the hand-held tester main switch ON. Check that the value of the illumination rate should change in the following range (0.8-22.0 ms) when the light sensor is put in the light or covered by a hand. This is the time to be taken for the light sensor to generate one circle of frequency according to the brightness. When not using the hand-held tester, see the «AUTOMATIC HEADLIGHTS & LIGHTING»(ref-152890) article under HEADLIGHTS in ACCESSORIES & EQUIPMENT. If the results are OK, go to the next step. If the results are not good, replace the light sensor. See «AUTOMATIC HEADLIGHTS & LIGHTING»(ref-152890) article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.
2. Check the wiring harness and connector between the light sensor and body ECU No. 2. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are OK, replace the body ECU No. 2. See «BODY ECU NO. 2»(ref-152690-S14036606732003022400000) under REMOVAL & INSTALLATION. If the results are not good, repair or replace the wiring harness or connector. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

The DTC is output when communication stops between the ECM (engine control module) and the body ECU No. 1. (Scheme 4) There is no communication from the ECM for more than 10 seconds.

Trouble Area

1. ECM.
2. Wiring Harness.

1. Check the ECM by checking that the engine starts normally. With this inspection, ECM can be diagnosed if it works normally or not. If the result is OK, go to the next step. If the result is not good, replace the ECM. See «ENGINE CONTROL MODULE (ECM)»(ref-152690-S33527723752003022400000) under REMOVAL & INSTALLATION.
2. Check the wiring harness by disconnecting the B5 connector of the body ECU No. 1, E5 of the ECM and A13 of the A/C amplifier. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the body ECU No. 1 and MPX1 of the ECM. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX2 of the ECM and MPX+ of the A/C amplifier. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If continuity exists in the wiring harness of both steps (A) and (B), or either (A) or (B), replace the ECM. See «ENGINE CONTROL MODULE (ECM)»(ref-152690-S33527723752003022400000) under REMOVAL & INSTALLATION. If the results are not good, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

The DTC is output when communication stops between the A/C amplifier and the body ECU No. 1. (Scheme 4) There is no communication from the A/C amplifier for more than 10 seconds.

Trouble Area

1. A/C Amplifier.
2. Wiring Harness.

1. Check the wiring harness by disconnecting the connector E5 of the ECM, G6 of the gateway ECU, C16 of the steering pad switch, T5 of the tilt and telescopic ECU and A/C amplifier. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between the terminals MPX+ of the A/C amplifier and MPX2 of the ECM. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between the terminals MPD1, MPD2 of the gateway ECU and MPX- of the A/C amplifier. On GS 430 model, check the continuity between terminals MPX1 of steering pad switch and MPX+ of the A/C amplifier. Check the continuity between the MPX1 of the tilt and telescopic ECU and MPX- of the A/C amplifier. If continuity exists in the wiring harness, replace the A/C amplifier. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC. If continuity does not exist, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
2. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when +B (battery voltage) or GND short occurs on the instrument panel system communication bus. If +B or GND short is detected on the instrument panel system communication bus, separate it by bus cut relay in the body ECU No. 1 and body ECU No. 2 to prevent while communication buses's failure. see scheme 3and (Scheme 8).

Trouble Area

1. Wiring Harness.
2. ECU (Instrument Panel System Bus).

Scheme 8

Note. On the system structure point of view, this DTC cannot display meter. In case of checking DTC, use hand-held tester.

1. Check the communication circuit inside the ECM by disconnecting the connector E5 of the ECM. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the ECM. See «ENGINE CONTROL MODULE (ECM)»(ref-152690-S33527723752003022400000) under REMOVAL & INSTALLATION. If the results are not good, go to the next step.
2. Check the communication circuit inside the A/C amplifier by connecting the connector E5 of the ECM and disconnecting the connector A13 of the A/C amplifier. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the A/C amplifier. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC. If the results are not good, go to the next step.
3. Check the communication circuit inside the gateway ECU by connecting the connector A13 of the A/C amplifier and disconnecting the connector G6 of the gateway ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the gateway ECU. See «GATEWAY ECU»(ref-152690-S03593609372003022400000) under REMOVAL & INSTALLATION. If the results are not good, go to then next step.
4. On vehicles with a steering pad switch, check the communication circuit inside steering pad switch by connecting the connector G6 of the gateway ECU and disconnecting the connector C16 of the steering pad switch. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the steering pad switch. See appropriate POWER TILT & TELESCOPIC STEERING COLUMN article in STEERING. If the results are not good, go to the next step.
5. Check the communication circuit inside the tilt and telescopic ECU by On vehicles with a steering pad switch, connect the connector C16 of the steering pad switch. On vehicles without a steering pad switch, connect the connector G6 of the gateway ECU. Disconnect the connector T5 of the tilt and telescopic ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the tilt and telescopic ECU. See appropriate POWER TILT & TELESCOPIC STEERING COLUMN article in STEERING.
6. Check the communication circuit inside the air bag sensor assembly by connecting the connector T5 of the tilt and telescopic ECU and disconnecting the connector C8 of the air bag sensor assembly. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the air bag sensor assembly. Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in «AIR BAG RESTRAINT SYSTEMS»(ref-150793) article. If the results are not good, go to the next step.
7. Check the communication circuit inside the instrument panel ECU by connecting the connector C8 of the air bag sensor assembly and disconnecting the connector C12 of the instrument panel ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the instrument panel ECU. See «INSTRUMENT PANEL»(ref-153134) article in ACCESSORIES & EQUIPMENT. If the results are not good, go to the next step.
8. Check the communication circuit inside the body ECU No. 2 by connecting the connector C12 of the instrument panel ECU and disconnecting the connector B6 of the body ECU No. 2. Remove the body ECU No. 2 from the driver side junction block. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, replace the body ECU No. 2. See «BODY ECU NO. 2»(ref-152690-S14036606732003022400000) under REMOVAL & INSTALLATION. If the results are not good, go to the next step.
9. Check for a short circuit between the instrument panel ECU and body ECU No. 2 by disconnecting the connector C12 of the instrument panel ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the instrument panel ECU and body ECU No. 2. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
10. Check for a short circuit between the instrument panel ECU and air bag sensor assembly by installing the body ECU No. 2 to the driver side junction block. Connect the connector B6 of the body ECU No. 2. Disconnect the connector C8 of the air bag sensor assembly. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the instrument panel ECU and the air bag sensor assembly. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
11. Check for a short circuit between the air bag sensor assembly and tilt and telescopic ECU by installing the body ECU No. 2 to the driver side junction block. Connect the connector B6 of the body ECU No. 2. Disconnect the connector T5 of the tilt and telescopic ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the air bag sensor assembly and the tilt and telescopic ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
12. Check for a short circuit between the tilt and telescopic ECU and gateway ECU by connecting the connector C8 of the air bag sensor assembly and disconnecting the connector G6 of the gateway ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the tilt and telescopic ECU and gateway ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
13. Check for a short circuit between the tilt and telescopic ECU and steering pad switch by connecting the connector G6 of the gateway ECU and disconnecting the connector C16 of the steering pad switch. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the steering pad switch and the tilt and telescopic ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
14. Check for a short circuit between the tilt and telescopic ECU and A/C amplifier by connecting the connector C16 of the steering pad switch and disconnecting the connector A13 of the A/C amplifier. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the tilt and telescopic ECU and the A/C amplifier. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
15. Check for a short circuit between the gateway ECU and A/C amplifier by connecting the connector T5 of the tilt and telescopic ECU and disconnecting the connector G6 of the gateway ECU. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the gateway ECU and A/C amplifier. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
16. Check for a short circuit between the gateway ECU and steering pad switch by connecting the connector A13 of the A/C amplifier and disconnecting the connector C16 of the steering pad switch. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the gateway ECU and steering pad switch. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
17. Check for a short circuit between the steering pad switch and A/C amplifier by connecting the connector G3 of the gateway ECU and disconnecting the connector A13 of the A/C amplifier. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between the steering pad switch and A/C amplifier. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
18. Check for a short circuit between the A/C ECU and ECM by connecting the connector C16 of the steering pad switch and disconnecting the connector E5 of the ECM. Check the DTC. The results are OK if DTC B1266/66 or B1267/67 is not output. If the results are OK, repair or replace the wiring harness between A/C amplifier and ECM. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . If the results are not good, go to the next step.
19. Check for a short circuit between the ECM and body ECU No. 1 by connecting the connector A13 of the A/C ECU and disconnecting the connector B5 of the body ECU No. 1. Check the wiring harness between ECM and body ECU No. 1. If the results are OK, replace the body ECU No. 1. See «BODY ECU NO. 1»(ref-152690-S23433460862003021900000) under REMOVAL & INSTALLATION. If the results are not good, repair or replace the wiring harness between ECM and body ECU No. 1. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
20. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communication stops between instrument panel ECU and body ECU No. 1. (Scheme 4) There is no communication from the instrument panel ECU for more than 10 seconds.

Trouble Area

1. Instrument Panel ECU.
2. Wiring Harness.

1. Check the instrument panel ECU by starting the engine and check that the speed meter and tachometer operate normally. With this inspection, the instrument panel ECU can be diagnosed if it works normally or not. If the results are OK, go to the next step. If the results are not good, replace the instrument panel ECU. See «INSTRUMENT PANEL»(ref-153134) article in ACCESSORIES & EQUIPMENT.
2. Check the wiring harness by disconnecting the connector B6 of the body ECU No. 2, C13 of the instrument panel ECU and C8 of the air bag sensor assembly. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX2 of the body ECU No. 2 and MPX- of the instrument panel ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX+ of the instrument panel ECU and MPX2 of the air bag sensor assembly. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If there is continuity in the wiring harness of both (A) and (B), or either (A) or (B), replace the instrument panel ECU. See «INSTRUMENT PANEL»(ref-153134) article in ACCESSORIES & EQUIPMENT. If the results are not good, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when the communication stops between the power seat ECU and body ECU No. 1. (Scheme 3) There is no communication from the seat ECU for more than 10 seconds.

Trouble Area

1. Power Seat ECU.
2. Wiring Harness.

1. Check the power seat ECU by checking that the operation of the front vertical and rear vertical is normal. With this inspection, the power seat ECU can be diagnosed if it works normally or not. If the results are OK, go to the next step. If the results are not good, replace the power seat ECU. See «POWER & HEATED SEATS»(ref-153185) article under SEATS in ACCESSORIES & EQUIPMENT.
2. Check the wiring harness by disconnecting the R13 connector of the rear right door ECU, P19 of the power seat ECU and R12 of the rear left door ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the rear right door ECU and MPX2 of the power seat ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX1 of the power seat ECU and MPX2 of the rear left door ECU. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If there is continuity in the wiring harness of both steps (A) or (B), or either (A) or (B), replace the power seat ECU. See «POWER & HEATED SEATS»(ref-153185) article under SEATS in ACCESSORIES & EQUIPMENT. If there is not continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when the communication stops between the moon roof ECU and body ECU No. 1. (Scheme 3) There is no communication from the moon roof ECU for more than 10 seconds.

Trouble Area

1. Moon Roof ECU.
2. Wiring Harness.

1. Check the moon roof ECU by checking that the operation of the moon roof function is normal. With this inspection, the moon roof ECU can be diagnosed if it works normally or not. If the results are OK, go to the next step. If the results are not good, replace the moon roof ECU. See «POWER MOON ROOF»(ref-153247) article.
2. Check the wiring harness by disconnecting the moon roof ECU and body ECU No. 1. The connector is disconnected by removing the body ECU No. 1 from the passenger side junction block. Check the continuity between terminals MPX2 of the body ECU No. 1 and MPX1 of the moon roof ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . If there is continuity in the wiring harness, replace the moon roof ECU. See «POWER MOON ROOF»(ref-153247) article under SUN ROOF/T-TOP/CONVERTIBLE TOP in ACCESSORIES & EQUIPMENT. If there is not continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

Note. No diagnostic procedure was provided by the manufacturer.

This DTC is output when communications between the air bag sensor assembly, instrument panel ECU and the tilt and telescopic ECU. (Scheme 3) There is no communication from the air bag sensor assembly for more than 10 seconds.

Trouble Area

1. Air Bag Sensor Assembly.
2. Wiring Harness.

1. Check the air bag sensor assembly by checking whether or not the DTC is output when changing to other air bag sensor assembly. The results are OK if a DTC is not output. If the results are OK, go to the next step. If the results are not good, replace the air bag sensor assembly (original air bag sensor assembly is failure). Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in «AIR BAG RESTRAINT SYSTEMS»(ref-150793) article.
2. Check the wiring harness by disconnecting the C8 connector of the air bag sensor assembly, C12 of the instrument panel ECU and T5 of the tilt and telescopic ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the air bag sensor assembly and MPX2 of the tilt and telescopic ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX2 of the air bag sensor assembly and MPX+ of the instrument panel ECU. If there is an OPEN in the wiring harness of either step (A) or (B), repair it. If continuity exists in the wiring harness of both steps (A) and (B), or either (A) or (B), replace the air bag sensor assembly. Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in «AIR BAG RESTRAINT SYSTEMS»(ref-150793) article. If there is not continuity, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communications between the steering pad switch and A/C amplifier. (Scheme 3) There is no communication from the air bag sensor assembly for more than 10 seconds.

Trouble Area

1. Steering Pad Switch.
2. Wiring Harness.

1. Check the steering pad switch by turning the ignition switch ON and check that the steering pad switch operate normally. If the results are OK, go to the next step. If the results are not good, replace the steering pad switch. See appropriate POWER TILT & TELESCOPIC STEERING COLUMN article in STEERING.
2. Check the wiring harness by disconnecting the G6 connector of the gateway ECU, A13 of the A/C amplifier ECU, T5 of the tilt and telescopic ECU and C15 of the steering pad switch. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPX1 of the steering pad switch and MPD1, MPD2 of the gateway ECU. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPX1 of the steering pad switch and MPX- of the A/C amplifier. Check the continuity between terminals MPX1 of the steering pad switch and MPX1 of the tilt and telescopic ECU. If there is an OPEN in the wiring harness of any terminals, repair it. If there is continuity in the wiring harness of both steps (A) and (B) or (A) and (C), or either (B) or (C), replace the steering pad switch. See appropriate POWER TILT & TELESCOPIC STEERING COLUMN article in STEERING. If there is not continuity as specified, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.

This DTC is output when communications between the tilt and telescopic ECU, A/C amplifier and gateway ECU. (Scheme 3) There is no communication from the gateway ECU for more than 10 seconds.

Trouble Area

1. Gateway ECU.
2. Wiring Harness.

1. Check if the gateway ECU operation is normal. If the results are OK, go to the next step. If the results are not good, replace the gateway ECU. See «GATEWAY ECU»(ref-152690-S03593609372003022400000) under REMOVAL & INSTALLATION.
2. Check the wiring harness by disconnecting the T5 connector of the tilt and telescopic ECU, A13 of the A/C amplifier ECU, C15 of the steering pad switch and G6 of the gateway ECU. See «CONNECTOR IDENTIFICATION»(ref-152690-S37521607892003022000000) . Check the continuity between terminals MPD1, MPD2 of the gateway ECU and MPX- of the A/C amplifier. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) . Check the continuity between terminals MPD1, MPD2 of the gateway ECU and MPX1 of the tilt and telescopic ECU. Check the continuity between terminals MPD1, MPD2 of the gateway ECU and MPX1 of the steering pad switch. If there is an OPEN in the wiring harness of any terminals, repair it. If there is continuity in the wiring harness of both steps (A) and (B) or (A) and (C), or either (B) or (C), replace the gateway ECU. See «GATEWAY ECU»(ref-152690-S03593609372003022400000) under REMOVAL & INSTALLATION. If there is not continuity as specified, repair or replace the wiring harness. See «WIRING DIAGRAMS»(ref-152690-S09032785552003021900000) .
3. After repairs have been made, perform confirmation test. See «CONFIRMATION TEST»(ref-152690-S26248412552003021900000) under SELF-DIAGNOSTIC SYSTEM.