Reading and Clearing Diagnostic Trouble Codes
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 volt.
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 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.
Self-diagnosis
When a problem is detected by self-diagnosis, the system does the following:
- Turns the SH-AWD indicator on.
- Memorizes the DTC.
- Stops AWD control and puts the vehicle back in FWD.
- Reduces engine torque to suit the driving conditions when the abnormality was detected.
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 assembly will usually come on, and the malfunction indicator lamp (MIL), the D5 indicator, and/or the ABS indicator may also come on.
1. With the ignition switch in LOCK (0), connect the HDS to the data link connector (DLC) (A) behind the driver's dashboard lower cover.
2. Turn the ignition switch to ON (II), make sure the HDS communicates with the vehicle and the SH-AWD control unit. If it doesn't, troubleshoot the DLC circuit Testing and Inspection and follow the prompts on the HDS to display the DTC(s) on the screen. 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.
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 (two required)
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 special tools 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 the 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.
