Differential: Other Honda Pilot I рестайлинг

VTM-4 Indicator

The VTM-4 indicator comes on under certain conditions even if the 4WD system is working normally. Here are some examples

1. When you use high-powered wireless equipment such as a CB or Ham radio in the vehicle.
2. When you keep spinning the front wheels while the vehicle is stuck in sand, mud, snow, etc.
3. 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.

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.

There are two methods used to initialize the VTM-4 control unit.

The recommended method is to use the Honda Diagnostic System (HDS) with the appropriate software plugged into the data link connector (DLC).

The other method is to initialize the VTM-4 control unit manually.

Scheme 67

1. With the ignition switch OFF, connect the HDS to the DLC (A).
2. Make sure the HDS communicates with the VTM-4 control unit. If it doesn't go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(ref-298125-S05538730862008091500000) ).
3. Turn the ignition switch ON (II), and follow the prompts on the HDS screen. NOTE: See the HDS user's manual for specific instruction.

Scheme 68

1. Start the engine (the VTM-4 indicator comes on, and the VTM-4 LOCK switch indicator is off).
2. Apply the brakes, and shift to either the R, 1, or 2 position, then push the VTM-4 LOCK switch (the VTM-4 indicator stays on, and the VTM-4 LOCK switch indicator is on). The 4WD system is now in lock mode.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON (II) (the VTM-4 indicator and the VTM-4 LOCK indicator both come on for 4 seconds, then go off). The VTM-4 control unit is initialized.

How to Check for DTCs

When the VTM-4 control unit senses an abnormality in the input or output systems, the VTM-4 indicator in the gauge control module will usually come on, and the malfunction indicator lamp (MIL), the D indicator, and/or the VSA indicator may also come on.

There are two methods used to check for DTCs.

The recommended method is to use the HDS with the appropriate software plugged into the data link connector DLC.

The other method is to connect the service check signal (SCS) circuit with the HDS. When the DLC is connected to the HDS, the VTM-4 indicator will blink the diagnostic trouble code (DTC) when the ignition switch is turned ON (II) and the SCS circuit is connected to body ground.

HDS Method

1. With the ignition switch OFF, connect the HDS to the DLC (A).
2. Make sure the HDS communicates with the VTM-4 control unit. If it doesn't go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(ref-298125-S05538730862008091500000) ).
3. 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»(ref-298126-S19284990342008091500000) . NOTE: See the HDS user's manual for specific instruction.
4. If there are fuel and emissions DTCs, A/T DTCs, or VSA DTCs at the same time, troubleshoot the fuel and emissions DTCs first, A/T DTCs second, VSA DTCs third, and VTM-4 DTCs last.
5. After recording the DTCs, clear all DTCs.
6. Test-drive the vehicle for several minutes in 4WD mode, and check for DTCs. If the DTC returns, refer to the «DTC TROUBLESHOOTING»(ref-298126-S19284990342008091500000) . 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.

Scheme 69

1. Park the vehicle on level ground. Shift to the P position, then turn off the engine.
2. Release the parking brake pedal.
3. With the ignition switch OFF, connect the HDS to the DLC (A).
4. Short the SCS circuit to body ground using the HDS.
5. Turn the ignition switch ON (II), and watch the VTM-4 indicator. NOTE: Codes above 10 are indicated by a series of long and short blinks. One long blink equals 10 short blinks. Add the long and short blinks together to determine the code. After determining the code, refer to the «DTC TROUBLESHOOTING»(ref-298126-S19284990342008091500000) .
6. Record all the DTC(s), then refer to the «DTC TROUBLESHOOTING»(ref-298126-S19284990342008091500000) to determine the meaning of each DTC.
7. Clear the DTCs from the VTM-4 control unit memory.
8. If the MIL, the D indicator, the VSA indicator, and the VTM-4 indicator all come on at the same time, troubleshoot the cause of the MIL first, then troubleshoot the A/T DTCs second, the VSA DTCs third, and the VTM-4 DTCs last.
9. Test-drive the vehicle for several minutes in 4WD mode, and check for DTCs. If the DTC returns, refer to the «DTC TROUBLESHOOTING»(ref-298126-S19284990342008091500000) . 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 Clear the VTM-4 Control Unit Memory

There are two methods used to clear DTCs from the VTM-4 control unit memory.

The recommended method is to use the HDS with the appropriate software plugged into the data link connector (DLC).

The other method is to connect the service check signal (SCS) connector with the HDS, and manually clear the memory.

1. With the ignition switch OFF, connect the HDS to the DLC (A).
2. Make sure the HDS communicates with the VTM-4 control unit. If it doesn't go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(ref-298125-S05538730862008091500000) ).
3. Turn the ignition switch ON (II), and follow the prompts on the HDS screen to clear the DTC(s). NOTE: See the HDS user's manual for specific instruction.

Scheme 70

1. Park the vehicle on level ground. Shift to the P position, then turn the ignition switch OFF.
2. Release the parking brake pedal.
3. With the ignition switch OFF, connect the HDS to the DLC (A).
4. Short the SCS circuit to body ground using the HDS.
5. Turn the ignition switch ON (II).
6. The VTM-4 indicator comes on and stays on for 4 seconds. Press and hold the VTM-4 LOCK switch while the VTM-4 indicator is on.
7. When the VTM-4 indicator goes off, release the VTM-4 LOCK switch.
8. The VTM-4 indicator comes on and stays on for 4 seconds. Push the VTM-4 LOCK switch while the VTM-4 indicator is on.
9. When the VTM-4 indicator goes off, release the VTM-4 LOCK switch. The VTM-4 indicator will blink twice quickly to confirm that the DTCs have been cleared from the VTM-4 control unit memory. NOTE: If the VTM-4 indicator does not blink twice quickly, the memory has not been cleared. Turn the ignition switch OFF, then repeat steps 5 through 9 .
10. Turn the ignition switch OFF, then disconnect the HDS from the DLC.

VTM-4 Control Unit Inputs and Outputs

The VTM-4 control unit terminal voltage and measuring conditions for the 4WD system are shown.

Note. Measure voltage with the connectors connected.

Scheme 71

CONNECTOR TERMINAL REFERENCE CHART

Scheme 72

Scheme 73

The VTM-4 LOCK indicator does not come on when the VTM-4 LOCK switch is pressed

Note. The VTM-4 LOCK indicator will only come on when the engine is running and the shift lever is in the R, 1, or 2 position before the switch is pressed.

Scheme 74

Scheme 75

Scheme 76

Scheme 77

Scheme 78

1. Check the No. 11 (7.5 A) and No. 9 (10 A) fuses in the driver's under-dash fuse/relay box. Are the fuses OK? YES - Go to step 2. NO - Replace the fuses, and recheck.
2. Turn the ignition switch ON (II), and check the VTM-4 LOCK indicator. Does the VTM-4 LOCK indicator come on with the ignition switch ON (II), and does it go off 4 seconds later? YES - Go to step 3. NO - Go to step 10 .
3. Start the engine, and move the shift lever to the R, 1, and 2 positions then check the VTM-4 LOCK indicator. Does the VTM-4 LOCK indicator come on when the VTM-4 LOCK switch is pushed? YES - The system is OK at this time. NO - Go to step 4.
4. Check for DTCs in the A/T system with the HDS. Are there any A/T DTCs indicated? YES - Go to the indicated DTC's troubleshooting. NO - Go to step 5.
5. Turn the ignition switch OFF.
6. Disconnect VTM-4 control unit connector A (22P) from the VTM-4 control unit.
7. Turn the ignition switch ON (II).
8. Measure voltage between the A8 terminal of the VTM-4 control unit and body ground. Is there battery voltage when the VTM-4 LOCK switch is pushed? YES - Check for loose terminal fit in the VTM-4 control unit connector. If it is normal, replace the VTM-4 control unit (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ). NO - Go to step 9.
9. Test the VTM-4 LOCK switch (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ). Is the VTM-4 LOCK switch OK? YES - Repair open in the wire between the VTM-4 LOCK switch and the VTM-4 control unit. NO - Replace the VTM-4 LOCK switch (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ).
10. Connect the A16 terminal of the VTM-4 control unit to body ground with a jumper wire, and watch the VTM-4 LOCK indicator. Does the VTM-4 LOCK indicator come on? YES - Check for loose terminal fit in the VTM-4 control unit connector. If it is normal, replace the VTM-4 control unit (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ). NO - Go to step 11.
11. Turn the ignition switch OFF.
12. Remove the VTM-4 LOCK switch.
13. Connect the No. 3 terminal of the VTM-4 LOCK switch 7P connector to body ground with a jumper wire.
14. Check for continuity between the A16 terminal of the VTM-4 control unit and body ground. Is there continuity? YES - Go to step 15. NO - Repair open in the wire between the A16 terminal and the VTM-4 LOCK switch.
15. Turn the ignition switch ON (II).
16. Measure voltage between the No. 2 terminal of the VTM-4 LOCK switch 7P connector and body ground. Is there battery voltage? YES - Replace the VTM-4 LOCK indicator bulb. NO - Repair open in the wire between the No. 2 terminal of the VTM-4 LOCK switch 7P connector and the driver's under-dash fuse/relay box.

Scheme 79

1. Disconnect VTM-4 control unit connector A (22P) from the VTM-4 control unit.
2. Turn the ignition switch ON (II), and check the VTM-4 LOCK indicator. Does the VTM-4 LOCK indicator come on with the ignition switch ON (II)? YES - Go to step 3. NO - Check for loose terminal fit in the VTM-4 control unit connectors. If it is normal, replace the VTM-4 control unit (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ).
3. Turn the ignition switch OFF.
4. Disconnect the VTM-4 LOCK switch connector.
5. Check for continuity between the A16 terminal of the VTM-4 control unit and body ground. Is there continuity? YES - Repair short to ground in the wire between the A16 terminal of the VTM-4 control unit and the VTM-4 LOCK switch. NO - Replace the VTM-4 LOCK switch (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ).

Scheme 80

Scheme 81

Scheme 82

Scheme 83

1. Disconnect VTM-4 control unit connector A (22P) from the VTM-4 control unit.
2. Turn the ignition switch ON (II).
3. Connect the A16 terminal of the VTM-4 control unit to body ground with a jumper wire, and check the VTM-4 LOCK indicator. Does the VTM-4 LOCK indicator come on? YES - Check for loose terminal fit in the VTM-4 control unit connectors. If it is normal, replace the VTM-4 control unit (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ). NO - Go to step 4.
4. Turn the ignition switch OFF.
5. Remove the VTM-4 LOCK switch (see «VTM-4 LOCK SWITCH TEST/REPLACEMENT»(ref-298126-S31051440492008091500000) ).
6. Connect the No. 3 terminal of the VTM-4 LOCK switch 7P connector to body ground with a jumper wire.
7. Check for continuity between the A16 terminal and body ground. Is there continuity? YES - Go to step 8. NO - Repair open in the wire between the A16 terminal of the VTM-4 control unit and the VTM-4 LOCK switch.
8. Turn the ignition switch ON (II).
9. Measure voltage between the No. 2 terminal of the VTM-4 LOCK switch 7P connector and body ground. Is there battery voltage? YES - Replace the VTM-4 LOCK indicator bulb. NO - Repair open in the wire between the No. 2 terminal of the VTM-4 LOCK switch 7P connector and the driver's under-dash fuse/relay box.

Scheme 84

1. Raise the vehicle on the lift.
2. Remove the oil filler plug (A) and sealing washer (B), then check the condition of the fluid, and make sure the fluid is at the proper level (C).
3. The fluid level must be up to the fill hole. If it is below the hole, add the recommended fluid until it runs out, then reinstall the oil filler plug with a new sealing washer.
4. If the differential fluid is dirty, remove the drain plug (D) and sealing washer, then drain the fluid.
5. Clean the drain plug, then reinstall it with a new washer, and refill the differential with the recommended fluid to the proper level. Fluid capacity: 2.64 L (2.79 US.qt) at fluid change 2.85 L (3.01 US.qt) at overhaul Recommended fluid: VTM-4 Differential Fluid (P/N 08200-9003)
6. Reinstall the oil filler plug with a new washer.

Note. Before doing the Differential Function Test, the following conditions must be present. No DTCs detected. Engine is not running. The VTM-4 control unit must be initialized.

1. Connect the HDS to the DLC.
2. Turn the ignition switch ON (II).
3. Make sure the HDS communicates with the VTM-4 control unit. If it doesn't go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(ref-298125-S05538730862008091500000) ).
4. Confirm that the temperature of the differential fluid is between 68°F (20°C) and 140°F (60°C) with the HDS.
5. Turn the ignition switch OFF with the shift lever in the P position.
6. Release the parking brake.
7. Raise the vehicle on the lift so all four wheels are off the ground.
8. Remove the rear wheels.
9. Turn the ignition switch ON (II).
10. Select MISCELLANEOUS TEST, then select the LEFT CLUTCH ELECTROMAGNETIC COIL TEST with the HDS, and follow the screen prompts. If the results are NORMAL, the left clutch is OK, go to step 9 . If the results are ABNORMAL, replace the rear differential.
11. Select MISCELLANEOUS TEST, then select the RIGHT CLUTCH ELECTROMAGNETIC COIL TEST with the HDS, and follow the screen prompts. If the results are NORMAL, the right clutch is OK. If the results are ABNORMAL, replace the rear differential.

Scheme 85

1. Drain the differential-fluid. Reinstall the drain plug with a new washer (see «REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT»(ref-298126-S41227010532008091500000) ).
2. Remove the wire harness cover (A), then disconnect the rear differential fluid temperature sensor 2P connector (B).
3. Remove the rear differential fluid temperature sensor (C).
4. Install the rear differential fluid temperature sensor in the reverse order of removal, with a new O-ring (D).
5. Refill the differential with the recommended differential fluid (see «REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT»(ref-298126-S41227010532008091500000) ).

Scheme 86

Scheme 87

1. Remove the center panel (see «CENTER PANEL REMOVAL/INSTALLATION»(ref-243318-S33281794622006082300000) ).
2. Disconnect the 7P connector from the VTM-4 LOCK switch, then remove the VTM-4 LOCK switch.
3. Check for continuity between the terminals in each switch position as shown (Scheme 87) If the switch fails any continuity check, replace the switch.