DTC 91

DTC 91 Chart:

Trans P/N Position Switch Circuit:

CIRCUIT DESCRIPTION
The transaxle range switch provides the Powertrain Control Module (PCM)with park/neutral range information for starting the vehicle as well as information for torque management and idle speed control.

DTC 9I WILL SET WHEN
Test 1:
- Engine speed changes from zero to non-zero without the park/neutral input to the PCM changing from "HI" to "LOW" (P/N to drive range).
- At least 5 seconds have past since a transition of the transaxle range switch.

Test 2:
- No DTCs 24,75 and 86.
- Park/neutral input to the PCM "LO" (in P/N).
- Engine operating.
- Throttle position 15.7 degrees or greater.
- Vehicle speed 7 mph or greater.
- Gear ratio of 3.11 or less (vehicle in gear).
- All conditions met for 5 seconds.

ACTION TAKEN (PCM WILL DEFAULT TO)
- With a current DTC 91 set, the PCM will illuminate the Malfunction Indicator Lamp (MIL) (Service Engine Soon).
- Disable cruise control.
- The PCM will use gear status from the transaxle pressure switch assembly for the transaxle range switch.

DTC 91 WILL CLEAR WHEN
The fault no longer exists and the ignition switch is cycled "OFF" and "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test checks the function of the transaxle range switch.
2. This test checks the switch and the adjustment.
3. This test checks the ground circuit.
4. This test checks CKT 434.
5. This test checks for a poor connection at the PCM or a bad PCM.

DIAGNOSTIC AIDS
This diagnostic test monitors the transaxle range switch for it to be closed when the vehicle is in gear or checks for an engine start while the transaxle switch is open (not in P/N).