GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: This table diagnoses the shift lever never being locked with the ignition switch in ON.

1

Were you sent here from the Brake Transmission Shift Interlock System Check?

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Go to Step 2

Go to Automatic Transmission Shift Lock Control System Check

2

  1. Disconnect the shift lock control module connector.
  2. Disconnect connector C3 of junction block 2.
  3. Test for a short to B+ in cavity 2 of the shift lock control module using a J 39200 .

Was a short to B+ condition measured in the GRN/WHT wire?

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Go to Step 3

Go to Step 4

3

Repair the short to B+ condition in the GRN/WHT wire between cavity 2 of the shift lock control module and cavity 1 of the stoplamp switch.

Is the repair complete?

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Go to Automatic Transmission Shift Lock Control System Check

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4

Test for continuity between cavity 7 of connector C3 of junction block 2 and cavity 2 of the shift lock control module connector.

Is there continuity?

--

Go to Step 5

Go to Step 6

5

Replace/adjust the stoplamp switch. Refer to Stop Lamp Switch Replacement or Stop Lamp Switch Adjustment in Hydraulic Brakes.

Is the replacement or adjustment complete?

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Go to Automatic Transmission Shift Lock Control System Check

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6

Replace the shift lock control module. Refer to Shift Lock Control Module Replacement in Automatic Transmissions 3 Speed - MB3 or Shift Lock Control Module Replacement in Automatic Transmissions 4 Speed - MS7.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

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