How To Troubleshoot The Body Electrical
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 battery for damage, state of charge, and clean and tight connections.
NOTICE:
* Do not quick-charge a battery unless the battery ground cable has been disconnected, otherwise you will damage the alternator diodes.
* Do not attempt to crank the engine with the battery ground cable loosely connected, or you will severely damage the wiring.
Handling Connectors
* Make sure the connectors are clean and have no loose wire terminals.
* Make sure multiple cavity connectors are packed with dielectric grease (except waterproof connectors).
* All connectors have push-down release type locks (A).
* Some connectors have a clip on their side used to attach them to a mount bracket on the body or on another component. This clip has a pull type lock.
* Some mounted connectors cannot be disconnected unless you first release the lock and remove the connector from its mount bracket (A).
* Never try to disconnect connectors by pulling on their wires; pull on the connector halves instead.
* Always reinstall plastic covers.
* Before connecting connectors, make sure the terminals (A) are in place and not bent.
* Check for loose retainers (A) and rubber seals (B).
* The backs of some connectors are packed with dielectric grease. Add grease if necessary. If the grease is contaminated, replace it.
* Insert the connector all the way and make sure it is securely locked.
* Position wires so that the open end of the cover faces down.
Handling Wires and Harnesses
* Secure wires and wire harnesses to the frame with their respective wire ties at the designated locations.
* Remove clips carefully; do not damage their locks (A).
* After installing harness clips, make sure the harness does not interfere with any moving parts.
* Keep wire harnesses away from exhaust components and other hot parts, from sharp edges of brackets and holes, and from exposed screws and bolts.
* Seat grommets in their grooves properly (A). Do not leave grommets distorted (B).
Testing and Repairs
* Do not use wires or harnesses with broken insulation. Replace them or repair them by wrapping the break with electrical tape or shrink tubing.
* Never attempt to modify, splice, or repair SRS wiring. If there is an open or damage in SRS wiring or terminals, replace the harness.
* After installing parts, make sure that no wires are pinched under them.
* When using electrical test equipment, follow the manufacturer's instructions and those described in this data.
* If possible, insert the probe of the tester from the wire side (except waterproof connectors).
* Use back probe adapter, 17mm 07TAZ-001020A.
* Refer to the instructions in the Honda Terminal Kit for identification and replacement of connector terminals.
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 ECM/PCM for DTCs and troubleshoot ECM/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 ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle.
NOTE: If the HDS does not communicate with the vehicle, troubleshoot the DLC circuit Testing and Inspection.
4. Select BODY ELECTRICAL, then select the desired MODE MENU, and check the 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.
NOTE: If DTC U1280 is stored, troubleshoot DTC U1280 first.
How to check for DTCs without the HDS (Use only if the HDS is unavailable)
If the HDS is unavailable, you can use the following method to check B-CAN communication status, DTCs, and some F-CAN communication status related with the gauge control module.
Check for DTCs
1. Turn the ignition switch to ON (II).
2. Pull and hold the combination light switch in its passing position.
3. Turn the combination light switch ON, then operate its passing position OFF and ON, then hold the passing position.
4. Turn the combination light switch OFF, and then ON, operating the switch two times repeatedly.
5. Release the combination light switch to its OFF position.
6. After 5 to 10 seconds, the DTCs which have been detected and stored individually by various B-CAN units will be indicated one by one on the multi-information display*1, or the information display*2, if the communication line between these display units, and the MICU, and the gauge control module, are OK.
To scroll through the DTCs, press the SEL/RESET button.
*1: With multi-information display unit
*2: With information display unit
With Multi-Information Display:
With Information Display:
The control unit that has stored the code be identified by the number shown on the multi-information display*1 or the information display*2.
*1: With multi-information display unit
*2: With information display unit
*1: With multi-information display unit
*2: With information display unit
NOTE: You can also check B-CAN communication status by the following methods:
* The MICU self-diagnostic function Test Mode 1 and Test Mode 2 can check some communication status and some switch circuits Initial Inspection and Diagnostic Overview.
* The gauge control module self-diagnostic function can check communication status Testing and Inspection.
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 ignition switch to ON (II).
3. Clear the DTCs with the HDS.
4. Turn the ignition switch to LOCK (0), and disconnect the HDS from the DLC.
How to Clear DTCs without the HDS
1. While in DTCs Indication Status, press and hold the SEL/RESET button for more than 10 seconds.
2. Turn the ignition switch to LOCK (0).
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:
* If an ECU is communicating with the HDS, "DETECT" will be displayed.
* If an ECU is not communicating, or the vehicle is not equipped with that ECU, "NOT AVAILABLE" will be displayed.
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.
TX: Transmitting units do not set loss of communication DTCs.