GM Service Manual Online
For 1990-2009 cars only
Table 1: Gear Position and Range Signal Chart

Circuit Description

The transmission range (TR) switch, or park/neutral position (PNP) is located on the selector shaft and informs the transmission control module (TCM) of the current selector lever position P-R-N-D-3-2-1.

The selector lever position is transmitted to the TCM in encoded form along 4 lines. The encoding is such that malfunctions in the connecting lead are identified.

The TR switch is located on the selector shaft, which is connected to the selector lever via a pull cable. In addition, the TR switch controls the starter interlock, the reverse lights and the selector lever position indicator on the instrument panel.

Conditions for Setting the DTC

    • The TR switch is stuck to closed.
    • The TR switch wiring harness is short to ground.
    • The TR switch wiring harness is short to power.
    • Immediately after the preceding condition occurs.

Action Taken When the DTC Sets

    • The malfunction indicator lamp (MIL) will illuminate.
    • The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
    • Adopt Emergency/Substitute mode and constant 4th gear.

Conditions for Clearing the MIL/DTC

    • The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles.
    • A history DTC will clear after 40 consecutive warm up cycles without a fault.
    • Using a scan tool can clear history diagnostic trouble codes (DTCs).

Diagnostic Aids

    • When DTC P0705 sets, the possible cause of TR switch.
    • An intermittent problem may be caused by a poor connection, rubbed-through wiring insulation, or a wire that is broken inside the insulation.
    • Any circuitry that is suspected as causing the complaint should be thoroughly inspected for the following conditions:
       - Backed-out terminals
       - Improper mating
       - Broken locks
       - Improperly formed
       - Damaged terminals
       - Poor terminal-to-wire connection

Gear Position and Range Signal Chart

Gear Position

L1

L2

L3

L4

P

0

0

12

0

R

0

0

0

12

N

0

12

0

0

D

12

12

12

0

3

12

12

0

12

2

12

0

12

12

1

0

12

12

12

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install the scan tool.
  2. Turn ON the ignition.
  3. Record, then clear the DTCs.
  4. Applying the brakes and select each transaxle range (P,R,N,D,3,2,1), while monitoring the scan tool. Refer to the Gear Position and Range Signal Chart.

Does each selected transaxle range match the scan tool and signal range chart?

--

Go to Step 3

Go to Diagnostic Aids

3

Inspect the F15 for shortage to ground.

Was the condition found?

--

Go to Step 4

Go to Step 5

4

Replace the fuse as necessary.

Is the action complete?

--

System OK

--

5

Inspect the neutral start switch. Refer to Diagnostic Aids.

Was the condition found?

--

Go to Step 6

Go to Step 7

6

Replace the neutral start switch.

Is the action complete?

--

System OK

--

7

  1. Disconnect the neutral start switch connector and transmission control module (TCM) connector.
  2. Measure the resistance between terminal 3 of the neutral start switch and terminal C1 of the TCM connector.
  3. Measure the resistance between terminal 2 of the neutral start switch and terminal B15 of the TCM connector.
  4. Measure the resistance between terminal 2 of the neutral start switch and terminal B6 of the TCM connector.
  5. Measure the resistance between terminal 5 of the neutral start switch and terminal B11 of the TCM connector.

Is the resistance equal to the specified value?

0 ohms

Go to Step 9

Go to Step 8

8

Repair the malfunctioning terminals as necessary.

Is the action complete?

--

System OK

--

9

  1. Turn the ignition ON.
  2. Measure the voltage of terminal 3.
  3. Measure the voltage of terminal 2.
  4. Measure the voltage of terminal 4.
  5. Measure the voltage of terminal 5.

Does the voltage measure within the specified value.

11-14 V

Go to Step 10

Go to Step 11

10

Repair the malfunctioning terminals as necessary.

Is the action complete?

--

System OK

--

11

Replace the TCM.

Is the action complete?

--

Go to Step 12

--

12

  1. After the repair, use a scan tool clear info function and road test the vehicle.
  2. Review the DTC info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 1

System OK