GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The transmission range (TR) switch is part of the park/neutral position (PNP) switch and is mounted on the transmission manual shaft. The TR switch is a multi-signal switch. The position signal is sent to the engine control module (ECM) by the transmission control module (TCM) using the CAN system.

When the powertrain control module (PCM) detects an invalid combination of TR switch signals, then DTC P0705 sets. DTC P0705 is a type C DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0705 Transmission Range (TR) Switch Circuit

Conditions for Running the DTC

    • The voltage of the transmission fluid temperature (TFT) sensor is between 0.1 and 2.4 volts.
    • The vehicle speed is more than 10 km/h (6 mph).
    • Engine speed is greater than 500 RPM.
    • Throttle position is greater than 13 percent.

Conditions for Setting the DTC

No input signal from the TR switch for more than 60 seconds

Action Taken When the DTC Sets

    • The TCM requests illumination of the malfunction indicator lamp (MIL).
    • The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Failure Records.
    • Lock-up control is inhibited.
    • The ECM stores DTC P0705 in PCM history.

Conditions for Clearing the DTC

    • A scan tool can clear the DTC.
    • The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
    • The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. By disconnecting the TR switch, the ground path for all TR switch circuits would be removed and the PCM should recognize all circuits as open. The scan tool should display HI for all range signals.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select TR Sw. on the scan tool.
  4. With the scan tool, observe the TR Sw. display while selecting each transmission range: P, R, N, D, 2 and D1.

Does each selected transmission range match the scan tool TR Sw. display?

--

Check system for intermittent circuit connections. Refer to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Inspect the park/neutral position (PNP) switch assembly for the following:
  2. • Damage
    • Loose or missing mounting hardware
    • Proper adjustment
  3. Inspect the shift cable for the following:
  4. • Damaged or stretched cable
    • Proper adjustment

Did you find and correct a condition?

--

Go to Step 12

Go to Step 4

4

With the scan tool, observe the TR Sw. display.

Does the scan tool TR Sw. Parameter indicate HI for all range signal states?

--

Go to Step 10

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the PNP switch connector.
  3. Turn ON the ignition, with the engine OFF.

Does the scan tool TR Sw. indicate HI for all range signal states?

--

Go to Step 6

Go to Step 10

6

Test the transmission range (TR) signal circuits of the PNP switch that did not indicate HI for a short to ground. Refer to Testing for Short to Ground .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 7

7

Test the TR signal circuits of the PNP switch that did not indicate proper voltage for an open. Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 8

8

Test the affected TR signal circuits of the PNP switch for a shorted together condition. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

9

Test the ground circuit of the PNP switch for an open. Refer to Testing for Continuity .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

10

Replace the PNP switch. Refer to Park/Neutral Position Switch Replacement .

Did you complete the replacement?

--

Go to Step 12

--

11

Replace the transmission control module (TCM). Refer to Transmission Control Module Replacement

Did you complete the replacement?

--

Go to Step 12

--

12

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Road test the vehicle.
  4. Select Specific DTC.
  5. Enter DTC P0705.

Has the test run and passed?

--

Go to Step 13

Go to Step 2

13

With the scan tool, observe the stored information, capture info and DTC info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK