GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Automatic Transmission Shift Lock Control System Check ?

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Go to Step 2

Go to Automatic Transmission Shift Lock Control System Check

2

  1. Turn the ignition switch to the RUN position.
  2. Place the gear selector lever in the PARK position.
  3. Disconnect stoplamp/BTSI switch connector C1.
  4. Press and hold the brake pedal.
  5. Attempt to move the gear selector lever to the NEUTRAL position.

Does the gear selector lever shift to the NEUTRAL position?

--

Go to Step 3

Go to Step 4

3

Replace the stoplamp/BTSI switch.

Is the repair complete?

--

Go to Step 7

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4

  1. Disconnect the shift interlock actuator connector.
  2. Connect a DMM between connector C1 terminal A and ground.

Is the measured voltage in the specified range?

Greater than 0.5V

Go to Step 5

Go to Step 6

5

Repair the short to battery positive voltage (B+) on CKT 1135 (DK GRN).

Is the repair complete?

--

Go to Step 7

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6

Replace the shift interlock actuator.

Is the repair complete?

--

Go to Step 7

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7

  1. Make sure any components removed during diagnosis are installed in place and that all connectors are connected.
  2. Repeat the system check. Refer to Automatic Transmission Shift Lock Control System Check .

Is the system check complete?

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System OK

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