GM Service Manual Online
For 1990-2009 cars only

Circuit Description


Object Number: 902195  Size: MF

The PCM determines which gear is selected by a combination of opens and grounds in circuits 771, 772, and 773 at the transaxle park/neutral position switch. Each combination indicates a specific selection on the manual shift quadrant, P, R, N, D, 2, or 3. Circuit 776 is either open or grounded to produce an even number of grounded circuits, 771, 772, 773, and 776. Invalid data indicates that the sum of the grounded circuits 771, 772, 773, and 776, in 1 of the manual shift quadrants is equal to an odd number.

Conditions for Setting the DTC

DTC P0706 is set when the PCM has detected an invalid bit pattern for more than 3.5 seconds, twice per ignition cycle.

The difference between DTC P0706 and DTC P0705 is that a possible bit pattern error due to misadjustment could set a DTC P0706.

Test Description

  1. This step verifies the conditions for DTC P0706 still exist.
  2. If the shift cable or switch is misadjusted, a DTC P0706 may set while in certain gear shift positions.
  3. DTC P0706 may set due to 1 or more circuits being shorted to ground. By disconnecting the switch, the PCM should read all circuits as high and the scan tool should display OPEN.
  4. This step will isolate an open circuit. As each individual circuit is grounded, the PCM/TCM should see the low signal and the tool should display INVALID.
  5. The PCM/TCM supplies a 12 volt signal to each transaxle park/neutral position switch circuit. This step tests for that voltage.
  6. DTC P0706 may have been set due to 1 of the circuits being shorted to voltage. This step verifies if a short to voltage exists.

Repair Verification

Monitor DTC menu Code Status for Pass Since Code Clear and Pass This Ignition Cycle. When both have passed, the repair is verified.

Criteria for pass:

    • No active DTC set.
    • Two valid selector positions are decoded. You must move the shifter to obtain a pass.

Diagnostic Aids

When the PCM detects a fault in the circuit, an open, ground, or short, the PCM will open the circuit internally to protect the circuit.

If no circuit problems can be detected, check the shift cable and switch adjustment.

Important: Refer to the chart from DTC P0705.

This DTC will cause the transaxle to start out in 2nd gear.


Object Number: 902521  Size: FP