Initial Inspection and Diagnostic Overview
How to Troubleshoot the Multiplex Integrated Control System
Troubleshooting CAN Circuit Related Problems
NOTE: Check the powertrain control module (PCM) for DTCs and troubleshoot PCM Initial Inspection and Diagnostic Overview or F-CAN loss of communication errors first.
You can easily check the F-CAN and B-CAN connection status and DTCs by using one of the following methods:
- The HDS (Preferred method) can check the F-CAN and B-CAN communication status, read and clear DTCs, display the data list, and perform function tests. Go to B-CAN System Diagnosis Test Mode A to check "Connected units" and DTCs. Troubleshooting - B-CAN System Diagnosis Test Mode A
- The AcuraLink Self-diagnostic Procedure can check communication status, and read and clear DTCs. How to Troubleshoot the AcuraLink (With AcuraLink)
- The gauge control module self-diagnosis function can check the F-CAN and B-CAN communication status. How to Troubleshoot the Gauges and Indicators
- The MID (multi-information display) can read and clear DTCs. Gauge Control Module DTC Display
- B-CAN System Diagnosis Test Mode 1 and Test Mode 2 can check communication status and test some switch circuits. Troubleshooting - B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS)
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
Without HDS (Use only if the HDS is unavailable)
1. Check for communication circuit problems using B-CAN System Diagnostic Test Mode A. Troubleshooting - B-CAN System Diagnosis Test Mode A
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 (beginning with the lowest number first; for example, if DTC B1005 and B1008 are retrieved, troubleshoot B1005 first). Refer to loss of communication cross reference chart.
-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)
BUS OFF and Internal Error Codes
BUS OFF and Internal Error Codes:
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.
