B1292

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1291,B1292: Short to B+ in Light System Communication Bus Malfunction

B1291 - Short to B+ in Light System Communication Bus Malfunction
B1292 - Short to GND in Light System Communication Bus Malfunction

DESCRIPTION

When a +B or body ground short circuit is detected on the light system communication bus (BEAN), the light system communication bus (BEAN) is disabled and a DTC is output.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK FOR DTC (NO. 1 JUNCTION BLOCK)





(a) Disconnect the LC No. 1 junction block connector.

(b) Turn the power switch ON (IG).

(c) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(d) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE NO. 1 JUNCTION BLOCK
NG -- Continue to next step.

2. CHECK FOR DTC (MAIN BODY ECU RH)





(a) Reconnect the LC No. 1 junction block connector.

(b) Disconnect the DA and K68 main body ECU RH connectors.

(c) Turn the power switch ON (IG).

(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(e) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- CHECK FOR DTC (MULTIPLEX TILT AND TELESCOPIC ECU)
NG -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (GATEWAY ECU - NO. 1 JUNCTION BLOCK AND MAIN BODY ECU RH)





(a) Disconnect the LC No. 1 junction block connector.

(b) Turn the power switch ON (IG).

(c) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(d) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

NG -- CHECK HARNESS AND CONNECTOR (GATEWAY ECU - NO. 1 JUNCTION BLOCK)
OK -- Continue to next step.

4. CHECK FOR DTC (FRONT CONTROLLER)





(a) Reconnect the LC No. 1 junction block connector.

(b) Reconnect the DA and K68 main body ECU RH connectors.

(c) Disconnect the 1X engine room No. 1 relay block connector.

(d) Turn the power switch ON (IG).

(e) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(f) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE ENGINE ROOM NO. 1 RELAY BLOCK, JUNCTION BLOCK (FRONT CONTROLLER)
NG -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - MAIN BODY ECU RH)





(a) Disconnect the DA and K68 main body ECU RH connectors.

(b) Turn the power switch ON (IG).

(c) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(d) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

NG -- CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - MAIN BODY ECU LH)
OK -- Continue to next step.

6. CHECK FOR DTC (COMBINATION SWITCH)





(a) Reconnect the 1X engine room No. 1 relay block, junction block and DA and K68 main body ECU RH connectors.

(b) Disconnect the K22 combination switch connector.

(c) Turn the power switch ON (IG).

(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(e) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE COMBINATION SWITCH
NG -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - COMBINATION SWITCH)





(a) Disconnect the 1X engine room No. 1 junction block connector.

(b) Turn the power switch ON (IG).

(c) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(d) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FRONT CONTROLLER - COMBINATION SWITCH)

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION SWITCH - MAIN BODY ECU RH)

8. CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - MAIN BODY ECU LH)





(a) Reconnect the DA and K68 main body ECU RH connectors.

(b) Disconnect the V3 and A30 main body ECU LH connectors.

(c) Turn the power switch ON (IG).

(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(e) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

Result





C -- CHECK FOR DTC (POSITION CONTROL ECU AND SWITCH LH)

B -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU LH - FRONT CONTROLLER)
A -- Continue to next step.

9. CHECK FOR DTC (AFS ECU)





(a) Reconnect the 1X engine room No. 1 relay block, junction block connector.

(b) Reconnect the V3 and A30 main body ECU LH connectors.

(c) Disconnect the A29 AFS ECU connector.

(d) Turn the power switch ON (IG).

(e) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(f) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE AFS ECU
NG -- Continue to next step.

10. CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - AFS ECU)





(a) Disconnect the 1X engine room No. 1 junction block connector.

(b) Turn the power switch ON (IG).

(c) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(d) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FRONT CONTROLLER - AFS ECU)
NG -- Continue to next step.

11. CHECK FOR DTC (MAIN BODY ECU LH)





(a) Reconnect the 1X engine room No. 1 relay block, junction block connector.

(b) Reconnect the A29 AFS ECU connector.

(c) Disconnect the V3 and A30 main body ECU LH connectors.

(d) Turn the power switch ON (IG).

(e) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(f) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE MAIN BODY ECU LH
NG -- Continue to next step.

12. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - AFS ECU)





(a) Disconnect the A29 AFS ECU connector.

(b) Turn the power switch ON (IG).

(c) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(d) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU LH - AFS ECU)
NG -- Continue to next step.

13. CHECK FOR DTC (POSITION CONTROL ECU AND SWITCH LH)





(a) Reconnect the V3 and A30 main body ECU LH and A29 AFS ECU connectors.

(b) Disconnect the b7 position control ECU and switch LH connector.

(c) Turn the power switch ON (IG).

(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(e) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE POSITION CONTROL ECU AND SWITCH LH (for Driver Side) Components

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POSITION CONTROL ECU - MAIN BODY ECU LH AND NO. 1 JUNCTION BLOCK)

14. CHECK FOR DTC (MULTIPLEX TILT AND TELESCOPIC ECU)





(a) Reconnect the LC No. 1 junction block connector.

(b) Reconnect the DA, DJ and K68 main body ECU RH connectors.

(c) Disconnect the K27 tilt and telescopic ECU connector.

(d) Turn the power switch ON (IG).

(e) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(f) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTCs B1291 and B1292 are not output.

OK -- REPLACE MULTIPLEX TILT AND TELESCOPIC ECU Components
NG -- Continue to next step.

15. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - TILT AND TELESCOPIC ECU)





(a) Disconnect the DA main body ECU RH connector.

(b) Measure the voltage and resistance of the wire harness side connectors.

Standard voltage:

Standard resistance










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU RH - TILT AND TELESCOPIC ECU)

OK -- REPLACE MAIN BODY ECU RH

16. CHECK HARNESS AND CONNECTOR (GATEWAY ECU - NO. 1 JUNCTION BLOCK)





(a) Reconnect the K27 multiplex tilt and telescopic ECU connector.

(b) Disconnect the K66 network gateway ECU connector.

(c) Disconnect the LC No. 1 junction block connector.

(d) Measure the voltage and resistance of the wire harness side connector.

Standard voltage:

Standard resistance










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GATEWAY ECU - NO. 1 JUNCTION BLOCK)
OK -- Continue to next step.

17. CHECK HARNESS AND CONNECTOR (NETWORK GATEWAY ECU - MAIN BODY ECU)





(a) Reconnect the LC No. 1 junction block connector.

(b) Disconnect the DA main body ECU RH connector.

(c) Measure the voltage and resistance of the wire harness side connector.

Standard voltage:

Standard resistance










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (NETWORK GATEWAY ECU - MAIN BODY ECU RH)

OK -- REPLACE NETWORK GATEWAY ECU