PGM-FI System

DTC Troubleshooting (cont'd)

11-527  

DTC 17: VSS Circuit Malfunction

  1. Reset the ECM/PCM (see page 11-468).
  2. Test-drive with no load (in Park or neutral), accelerate to 4,000 rpm (min-1), then decelerate to 1,500 rpm (min-1) with throttle fully closed for at least 5 seconds.

Is the MIL on and does it indicated DTC 17?

YES

- Go to step 3.

NO

- Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the VSS and at the ECM/PCM.


  1. Turn the ignition switch OFF.
  2. Block the rear wheels and set the parking brake.
  3. Raise the front of the vehicle, and make sure it is securely supported.
  4. Turn the ignition switch ON (II).
  5. Block the right front wheel, and slowly rotate the left front wheel.
  6. Measure voltage between ECM/PCM connector terminals A18 and A24.

ECM/PCM CONNECTOR A (31P)

Wire side of female terminals

Does the voltage pulse between 0 V and 5 V (or battery voltage)?

YES

- Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/PCM.

NO

- Go to step 9.


  1. Turn the ignition switch OFF.
  2. Disconnect ECM/PCM connector A (31P).
  3. Turn the ignition switch ON (II).
  4. Block the right front wheel, and slowly rotate the left front wheel.
  5. Measure voltage between the ECM/PCM connector terminals A18 and A24.

ECM/PCM CONNECTOR A (31P)

Wire side of female terminals

Does the voltage pulse between 0 V and 5 V?

YES

- Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.

NO

- Check these items:


  • A short or an open in the wire between the ECM/PCM (A18) and the VSS.
  • If the wire is OK, test the VSS (see page 22-94).