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 RUN.
  2. Place the gear selector lever in PARK.
  3. Connect a digital multimeter (DMM) between the park/neutral position switch connector terminal B (PNK) and ground. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.

Is the measured voltage in the specified range?

10-15V

Go to Step 3

Go to Step 4

3

Connect a fused jumper between the park/neutral position switch connector terminal B (PNK) and C (LT GRN). Refer to Using Fused Jumper Wires in Wiring Systems.

Does the shift interlock solenoid hold the gear selector lever in PARK with the brake pedal not pressed?

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Go to Step 5

Go to Step 6

4

  1. Inspect the T/SIG/BULP BTSI fuse 1B in the IP fuse block.
  2. If the fuse is OK, inspect CKT 539 (PNK) for an open. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 15

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5

  1. Connect the park/neutral position switch.
  2. Disconnect the stoplamp/BTSI switch connector  C1 terminal  B (DK GRN/WHT).
  3. Connect a DMM between the stoplamp/BTSI switch connector   C1 terminal A (LT GRN) and ground. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.

Is the measured voltage in the specified range?

10-15V

Go to Step 7

Go to Step 8

6

  1. Test the park/neutral position switch connector for proper terminal contact. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
  2. If terminal contact is OK, replace the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transaxle 4T65E.

Is the repair complete?

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Go to Step 15

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7

Connect a DMM between the stoplamp/BTSI switch connector C1 terminal A (LT GRN) and B (DK GRN/WHT). Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.

Is the measured voltage in the specified range?

10-15V

Go to Step 10

Go to Step 9

8

Repair the open in CKT 275 (LT GRN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 15

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9

  1. Connect the stoplamp/BTSI switch connector C1.
  2. Disconnect the shift interlock actuator connector.
  3. Connect a DMM between the shift interlock actuator connector terminal A (DK GRN/WHT) and ground. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.

Is the measured voltage in the specified range?

10-15V

Go to Step 11

Go to Step 12

10

  1. Test the stoplamp/BTSI switch connector C1 for proper terminal contact.
  2. If the terminal contact is OK, then replace the stoplamp/BTSI switch.

Is the repair complete?

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Go to Step 15

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11

Connect a DMM between the shift interlock actuator connector terminal A (DK GRN/WHT) and B (BLK).

Is the measured voltage in the specified range?

10-15V

Go to Step 14

Go to Step 13

12

Repair the open in CKT 1135 (DK GRN/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 15

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13

  1. Inspect ground G202 for proper terminal contact.
  2. If OK, repair the open in CKT 1250 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 15

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14

  1. Test the shift interlock actuator connector for proper terminal contact.
  2. If the connector terminal contact is OK, then replace the shift interlock actuator.

Is the repair complete?

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Go to Step 15

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15

  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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