Initial Inspection and Diagnostic Overview
How to Troubleshoot the SH-AWD System
SH-AWD Indicator
The SH-AWD indicator comes on under certain conditions even if the AWD system is working normally. Here are some examples:
- When you use high-powered wireless equipment such as a CB or Ham radio in the vehicle.
- When you keep spinning the rear wheels while the vehicle is stuck in sand, mud, snow, etc.
- When the battery voltage suddenly drops below 10 volts.
After the SH-AWD indicator comes on, it stays on until you turn the ignition switch to LOCK (0).
Diagnostic Trouble Code (DTC)
- The SH-AWD control unit can memorize up to eight different DTCs. The system displays the DTCs by blinking the SH-AWD indicator. Multiple DTCs are displayed in the order they occurred, beginning with the most recent.
- If the same DTC is detected more than once, the most recent DTC is written over the earlier one. Therefore, when the same problem is detected more than once, it is memorized as a single DTC.
- The DTCs are memorized in the SH-AWD units EEPROM (non-volatile memory). Therefore, the memorized DTCs are not cleared when the battery is disconnected or when the SH-AWD control unit is disconnected.
- If there is a problem in the central processing unit (CPU) of the SH-AWD control unit, the SH-AWD indicator comes on, but no DTC is memorized. Refer to the symptom troubleshooting.
Self-diagnosis
When a problem is detected during self-diagnosis, the system does the following:
- Turns the SH-AWD indicator on.
- Memorizes the DTC if possible.
- Stops AWD control and puts the vehicle back into two-wheel drive (front wheel only).
- Reduces engine torque to suit the driving conditions when an abnormality was detected (The client may notice a decrease in engine performance).
How to Use the HDS (Honda Diagnostic System)
1. With the ignition switch in LOCK (0), connect the Honda diagnostic system (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 and the SH-AWD control unit. If it does not, go to the DLC circuit troubleshooting Testing and Inspection.
4. Check the diagnostic trouble code (DTC) and the freeze data, for all systems in the vehicle, troubleshoot the powertrain DTCs first and note them. Then refer to the indicated DTC's troubleshooting, and do the appropriate troubleshooting procedure.
NOTE:
- The HDS can read the DTC, the freeze data, the current data, and other system data.
- For specific operations, refer to the help menu that came with the HDS.
- It is best do an ALL DTC CHECK to look for other systems DTCs that are related to the problem.
How to Clear DTCs
1. With the ignition switch in LOCK (0), connect the HDS to the 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 and the SH-AWD control unit. If it does not go to the DLC circuit troubleshooting Testing and Inspection.
4. Clear the DTC(s) by following the screen prompts on the HDS.
5. Turn the ignition switch to LOCK (0).
NOTE: If the DTC that was cleared is related to another system, that system's DTC must be repaired, or the SH-AWD DTC will return.
How to Check for Diagnostic Trouble Codes (DTCs)
When the SH-AWD control unit senses an abnormality in the input or output systems, the SH-AWD indicator in the gauge control module will usually come on, and the malfunction indicator lamp (MIL), the D indicator, the VSA indicator, and/or the ABS indicator may also come on.
NOTE: Check the vehicle battery condition and charging system before troubleshooting.
1. With the ignition switch in LOCK (0), connect the HDS to the DLC (A) located under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II), make sure the HDS communicates with the vehicle and the SH-AWD control unit. If it does not, go to the DLC circuit troubleshooting Testing and Inspection. Follow the prompts on the HDS to display the DTC(s) on the screen. Check the DTC and the freeze data for all systems. After determining the DTC(s), refer to the DTC Troubleshooting.
NOTE: See the HDS help menu for specific instruction.
3. If there are fuel and emission DTCs, A/T DTCs, and VSA system DTC's at the same time, troubleshoot the fuel and emission DTCs first, otherwise the SH-AWD DTC may return.
4. After recording the DTCs, clear all DTCs.
5. Test-drive the vehicle for several minutes in AWD mode, and check for DTCs. If the DTC returns, refer to the DTC Troubleshooting. If the DTC does not return, there was an intermittent problem within the circuit. Make sure all connectors and terminals in the circuit are tight.
How to Troubleshoot Circuits at the SH-AWD Control Unit
Special Tools Required
- Backprobe Set 07SAZ-001000A (2)
1. Remove the rear left side trim panel cover (A).
2. Loosen the SH-AWD control unit mounting bolts (A), then remove the SH-AWD control unit (B).
3. Inspect the circuit on the SH-AWD control unit according to the DTC Troubleshooting using the backprobe set and a digital multimeter or an analog circuit tester.
4. Connect the backprobe adapters (C) to the stacking patch cords (D), and connect the cords to a digital multimeter or an analog circuit tester (E). Using the wire insulator as a guide for the contoured-tip of the backprobe adapter, gently slide the tip into the connector from the wire side until it comes in contact with the terminal end of the wires.