GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Content Theft Deterrent (CTD) System Check?

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Go to Step 2

Go to Content Theft Deterrent (CTD) System Check

2

  1. Turn ignition switch on.
  2. Install the scan tool.
  3. Select the following items:
  4. • The Driver Door Module (DDM)
    • The Data Display
    • The Inputs
  5. Operate the LH and RH front door lock cylinder switches.

Does the scan tool show an input for both front door lock switches?

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Go to Step 3

Go to Step 4

3

Replace the remote function actuator (RFA) module. Refer to Remote Control Door Lock Receiver Replacement in Keyless Entry.

Did you complete the repair?

--

Go to Content Theft Deterrent (CTD) System Check

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4

  1. Disconnect connector C3 of the malfunctioning front door lock cylinder switch.
  2. Operate the malfunctioning door lock cylinder switch while you use a digital multimeter (DMM) to measure resistance.
  3. Measure resistance of the front door lock cylinder switch, connector C3, and the corresponding terminals:
  4. • The LH terminals J and K
    • The RH terminals G and H

Is the resistance within the specified range?

0-5 ohms

Go to Step 5

Go to Step 6

5

Replace the door module in that door. Refer to Front Door Module Replacement in Doors.

Did you complete the repair?

--

Go to Content Theft Deterrent (CTD) System Check

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6

Test for an open or short to ground in the following CKTs:

    • The LH front door lock cylinder switch 262 (LT GRN)
    • The RH front door lock cylinder switch 265 (LT GRN)

Is the circuit OK?

--

Go to Step 8

Go to Step 7

7

Repair the open or short to ground in the following CKTs:

    • The LH front door lock cylinder switch 262 (LT GRN)
    • The RH front door lock cylinder switch 265 (LT GRN)
        Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Content Theft Deterrent (CTD) System Check

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8

Test for an open or short to ground in the following CKTs:

    • The LH front door lock cylinder switch 536 (LT GRN/BLK)
    • The RH front door lock cylinder switch 537 (LT GRN/BLK)

Is the circuit OK?

--

Go to Step 10

Go to Step 9

9

Repair the open or short to ground in the following CKTs:

    • The LH front door lock cylinder switch 536 (LT GRN/BLK)
    • The RH front door lock cylinder switch 537 (LT GRN/BLK)
        Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Content Theft Deterrent (CTD) System Check

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10

Replace the malfunctioning front door lock cylinder switch. Refer to Door Lock Cylinder Replacement in Doors.

Did you complete the repair?

--

Go to Content Theft Deterrent (CTD) System Check

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