Initial Inspection and Diagnostic Overview

How to Troubleshoot the Multiplex Integrated Control System

Troubleshooting CAN Circuit Related Problems

NOTE: Check the ECM/PCM for DTCs and troubleshoot ECM/PCM Initial Inspection and Diagnostic Overview or F-CAN loss of communication errors first.

Using the HDS (Preferred method)

1. Go to B-CAN System Diagnosis Test Mode A to check for "Connected units" and DTCs. Troubleshooting - B-CAN System Diagnosis Test Mode A

2. If no DTCs are retrieved, go to B-CAN System Diagnosis Test Mode C Troubleshooting - B-CAN System Diagnosis Test Mode C or D. Troubleshooting - B-CAN System Diagnosis Test Mode D

Using the B-CAN System Diagnosis Test Mode 1 (Use only if the HDS is unavailable)

1. Check for communication circuit problems using B-CAN System Diagnostic Test Mode 1. Troubleshooting - B-CAN System Diagnosis Test Mode 1 And Test Mode 2 (Without The HDS)

2. Check for DTCs.

3. Sort, and then troubleshoot the DTCs in this order.
-1 Battery voltage DTCs
-2 Internal error DTCs
-3 Loss of communication DTCs
-3 NOTE: If the DTC U1280 is stored, troubleshoot DTC U1280 first.
-4 Signal error DTCs

4. If no DTCs are retrieved, use B-CAN System Diagnostic Test Mode 2 to check all inputs related to the failure. Troubleshooting - B-CAN System Diagnosis Test Mode 1 And Test Mode 2 (Without The HDS)

How to display DTCs on the gauge control module

Enter the B-CAN System Diagnosis Test Mode 1. Troubleshooting - B-CAN System Diagnosis Test Mode 1 And Test Mode 2 (Without The HDS) While in Test Mode 1, the DTCs which have been detected and stored individually by various B-CAN (Body-controller Area Network) units, will be shown one by one on the LCD display when the communication between the MICU and the gauge control module is normal. To scroll through the DTCs, press the select/reset button.






The unit that has stored the code can be identified by the number shown on the odometer display.





How to clear the DTC

Enter the B-CAN System Diagnosis Test Mode 1. Troubleshooting - B-CAN System Diagnosis Test Mode 1 And Test Mode 2 (Without The HDS) While in Test Mode 1, press and hold down the SELECT/RESET button for more than 10 seconds.

Loss of Communication DTC cross-reference chart

When an ECU is unable to communicate with the other ECUs on the CAN circuit, the other control units will set loss of communication DTCs. Use this chart to find the control unit that is not communicating.

1. Find the Transmitting Control Unit that is in the same row as all of the loss of communication DTCs retrieved.

2. Do the input test for the transmitting control unit.

BUS OFF and Internal Error Codes





Loss of Communication





TX: Transmitting unit does not set a loss communication DTC.