HOW TO TROUBLESHOOT THE BODY ELECTRICAL
Tips and Precautions
Special Tools Required
Back Probe Adapter, 17 mm 07TAZ-001020A
Before Troubleshooting
1. Check applicable fuses in the appropriate fuse/relay box.
2. Check the 12 volt battery for damage, state of charge, and clean and tight connections.
Handling Connectors
Handling Wires and Harnesses
Testing and Repairs
Five-Step Troubleshooting
1. Verify The Complaint: Turn on all the components in the problem circuit to verify the customer complaint.
Note the symptoms. Do not begin disassembly or testing until you have narrowed down the problem area.
2. Analyze The Schematic: Look up the schematic for the problem circuit. Determine how the circuit is supposed to work by tracing the current paths from the power feed through the circuit components to ground. If several circuits fail at the same time, the fuse or a ground is a likely cause. Based on the symptoms and your understanding of the circuit operation, identify one or more possible causes of the problem.
3. Isolate The Problem By Testing The Circuit: Make circuit tests to check the diagnosis you made in step 2.
Keep in mind that a logical, simple procedure is the key to efficient troubleshooting. Test for the most likely cause of failure first. Try to make tests at points that are easily accessible.
4. Fix The Problem: Once the specific problem is identified, make the repair. Be sure to use proper tools and safe procedures.
5. Make Sure The Circuit Works: Turn on all components in the repaired circuit in all modes to make sure you've fixed the entire problem. If the problem was a blown fuse, be sure to test all of the circuits on the fuse.
Make sure no new problems turn up and the original problem does not recur.
Wire Color Codes
The following abbreviations are used to identify wire colors in the circuit schematics:
The wire insulation has one color or one color with another color stripe. The second color is the stripe.
Troubleshoot the B-CAN Circuit Related Problems
Check the PCM for DTCs and troubleshoot PCM or F-CAN loss of communication errors first.
How to check for DTCs with the HDS (preferred method)
The HDS can check F-CAN and B-CAN communication status, read and clear DTCs, display data list, and perform function tests.
Check for DTCs
1. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
2. Turn the vehicle to the ON mode, but do not start the engine.
3. Make sure the HDS communicates with the vehicle.
NOTE: If the HDS does not communicate with the vehicle, troubleshoot the DLC circuit.
4. Select BODY ELECTRICAL, then select the desired MODE MENU, and check for DTCs. If the DTCs do not pertain to the select menu, select the ALL DTC Check icon to view all Body Electrical DTCs.
NOTE: For specific operations, refer to the HDS user's manual.
5. If any DTCs are indicated, go to the indicated DTCs troubleshooting.
How to Clear DTCs with the HDS
1. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
2. Turn the vehicle to the ON mode
3. Clear the DTCs with the HDS
4. Turn the vehicle to the OFF (LOCK) mode, and disconnect the HDS from the DLC.
B-CAN Circuit Troubleshooting Information
1. Connect the HDS to the data link connector (DLC)
2. From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS
3. Check that the electronic control units (ECU) are communicating with the HDS.
NOTE :
4. If a control unit is not communicating, confirm which ECUs are communicating, then refer to the B-CAN Communication Line from the Electrical Wiring Diagrams to find the malfunction point.For example, when unit "K" is communicating, but units "G", "M", and "N" are not communicating, that will direct you to the malfunction point (A).
Loss of Communication DTC Cross-Reference Chart
When an ECU on the CAN circuit is unable to communicate with other ECUs on the CAN circuit, the other control units will set loss of communication DTCs. Use this chart to find the ECU that is not communicating with the other ECUs on the CAN circuit.
1. Find the Transmitting Control Unit that is in the same row as all of the loss of communication DTCs that you retrieved
2. Do the input test for the transmitting control unit.
BUS OFF and Internal Error Codes
Loss of Communication
TX: Transmitting units do not set loss of communication DTCs.