Displaying & Reading Trouble Codes
VTM-4 IndicatorThe VTM-4 indicator comes on under certain conditions even if the 4WD 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 8 volts or rises above 16 volts.
After the VTM-4 indicator comes on, it stays on until you turn the ignition switch off.
Diagnostic Trouble Code (DTC)
- The VTM-4 control unit can memorize up to seven different DTCs. The system displays the DTCs by blinking the VTM-4 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 the VTM-4 control unit is disconnected.
- If there is a problem in the central processing unit (CPU) of the VTM-4 control unit, the VTM-4 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 VTM-4 indicator on. Memorizes the DTC.
- Stops 4WD control and puts the vehicle back in 2WD (FWD).
- Reduces engine torque to suit the driving conditions when the abnormality was detected.
Initialization of the VTM-4 Control Unit
Whenever the VTM-4 control unit is replaced, it must be initialized to make the 4WD system function.
1. With the ignition switch OFF, connect the HDS to the 16P DLC (A) located behind the driver's dashboard lower cover.
2. Turn the ignition switch ON (II), and follow the prompts on the HDS screen.
NOTE: See the HDS help menu for specific instruction.
How to Check for Diagnostic Trouble Codes (DTCs)
When the VTM-4 control unit senses an abnormality in the input or output systems, the VTM-4 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 OFF, connect the HDS to the 16P DLC (A) behind the driver's dashboard lower cover.
2. Turn the ignition switch ON (II), 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 Index.
NOTE: See the HDS help menu for specific instruction.
3. If there are fuel and emission DTCs, A/T DTCs, and Vehicle Stability Assist (VSA) 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 4WD mode, and check for DTCs. If the DTC returns, refer to the DTC Troubleshooting Index. 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.