GM Service Manual Online
For 1990-2009 cars only

Go to Cell 133: VDT PASS-Key System

Circuit Description

The PASS-Key® III Theft Deterrent (VTD) Module controls the starter relays at connector terminal G, CKT 625 (YEL/BLK). The VTD module monitors this output to determine if it is within a valid operating range.

Conditions for Setting the DTC

The PASS-Key® III Theft Deterrent (VTD) Module detects that CKT 625 (YEL/BLK) is shorted to ground for approximately 1.2 seconds or more.

Action Taken When the DTC Sets

    • Stores a DTC B3028 in the VTD module memory.
    • No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

    • The PASS-Key® III Theft Deterrent (VTD) Module detects that CKT 625 (YEL/BLK) is no longer shorted to ground for approximately 1.2 seconds or more.
    • Use the On-Boards clearing DTCs feature. Refer to OBSD Procedure.
    • Use a scan tool.

Diagnostic Aids

Check circuit 625 (YEL/BLK) for a short to ground.

Test Description

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

  1. Perform the Theft Deterrent System Diagnostic System Check before continuing with the diagnosis of this DTC.

  2. Determines whether the malfunction is in the underhood junction block.

  3. Determines whether the malfunction is in the circuit or the VTD module.

  4. Clear all DTCs after the repair procedure is complete.

DTC B3028

Step

Action

Value(s)

Yes

No

1

Was the Theft Deterrent System Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Remove the key from the ignition switch.
  2. Disconnect the underhood junction block connector C2.
  3. Connect a DMM between the underhood junction block connector C2, terminal A2 and ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step 3

Go to Step 6

3

  1. Disconnect the VTD module connector.
  2. Connect a DMM between the connector terminal G, CKT 625 and ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step 5

Go to Step 4

4

Replace the PASS-Key® III Theft Deterrent (VTD) Module. Refer to Theft Deterrent Module Replacement .

Refer to PASSLOCK Reprogramming Auto Learn .

Is the replacement complete?

--

Go to Step 7

--

5

Repair the short to ground in circuit 625 (YEL/BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 7

--

6

Replace the underhood junction block. Refer to Underhood Fuse Block Replacement in Engine Electrical.

Is the replacement complete?

--

Go to Step 7

--

7

  1. Turn OFF the ignition.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn ON the ignition.
  4. Clear any DTCs. Refer to Clearing DTCs .

Are all DTCs cleared?

--

Go to Diagnostic System Check - Theft Deterrent

--