GM Service Manual Online
For 1990-2009 cars only

Object Number: 647262  Size: LF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The AT manual shaft shift position switch is attached externally to the left side of the 4L30-E transmission. The AT manual shaft shift position switch informs the transmission control module (TCM) and the console gear position indicator which gear the driver selects.

Ignition voltage is supplied to the switch on terminal D. Depending on the selector lever position, the ignition voltage connects to various combinations of terminals A, B, C, and G of the AT manual shaft shift position switch. The TCM decodes these combinations in order to determine gear selector lever position. Refer to the Automatic Transmission Manual Shift Shaft Position Switch Logic Table . When the TCM detects Park or Neutral with throttle position and engine speed for a period of time or the TCM detects Reverse with high transmission output speed, DTC P0706 will set. DTC P0706 is a type C DTC.

Conditions for Running the DTC

    • The TCM detects that the gear selector is set to NEUTRAL or PARK.
    • The engine speed is greater than 500 RPM but less than 3008 RPM.
    • The throttle position is greater than 34 percent.
    • All conditions present for 3.8 seconds.

Conditions for Setting the DTC

Position N or P is detected.

Action Taken When the DTC Sets

    • The TCM uses D for the Trans Range default value.
    • The TCM does not request the ECM to illuminate the MIL.
    • The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM records this information as Failure Records.
    • The TCM stores DTC P0706 in TCM history.

Conditions for Clearing the DTC

    • A scan tool can clear the DTC.
    • The TCM clears the DTC from TCM history if the vehicle completes 40  warm-up cycles without a non-emission-related diagnostic fault occurring.
    • The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids

Refer to the Automatic Transmission Manual Shift Shaft Position Switch Logic Table .

Test Description

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

  1. If the Manual Shaft Shift Position Switch is electrically faulty, P0705 will set. If P0705 is set with P0706, diagnose and repair P0705 first.

  2. The Scan Tool display should match the selector lever position at each detent. If you have to move the lever slightly within a position to get the right indication on theScan Tool , the Transmission Range Switch adjustment should be checked. Refer to Manual Shift Shaft Position Switch Replacement .

Step

Action

Value(s)

Yes

No

1

Did you perform Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission ?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission

2

Is DTC P0705 in TCM history?

--

Go to DTC P0705

Go to Step 3

3

  1. Install a Scan Tool .
  2. Turn ON the ignition with the engine OFF.
  3. Select the transmission data display.
  4. Apply the brakes.
  5. Select each transmission range, pausing momentarily in each range, while observing the Trans Range parameter on the Scan Tool .

Does each selected transmission range match the Scan Tool display?

--

Go to Intermittent Conditions in Engine Controls

Go to Step 4

4

Inspect the Manual Shaft Shift Position Switch for:

    • Loose or missing mounting hardware
    • Switch collar slipping around the transmission manual shaft
    • Damage
    • Improper adjustment
    • Loose or damaged linkage

Did you find and correct the condition?

--

Go to Step 6

Go to Step 5

5

Replace the Manual Shaft Shift Position Switch.

Refer to Manual Shift Shaft Position Switch Replacement .

Did you complete the replacement?

--

Go to Step 6

--

6

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
  4. • Drive the vehicle in D range with a throttle position greater than 34%.
    • Ensure that the engine RPM is greater than 3,008 after 3.8 seconds.

Did DTC P0706 reset?

--

Go to Step 1

System OK