For 1990-2009 cars
Theft Deterrent System Components
Cell 133: Fuel Tank Module, Instrument Cluster and Passlock Cylinder
Handling ESD Sensitive Parts Notice

### Circuit Description

This circuit supplies the Passlock™ data to the body control module (BCM) from the Passlock™ sensor, CKT 1836.

### Conditions for Setting the DTC

All of the following conditions must be met:

• | The Passlock™ option is enabled.

• | Ignition 0 is active.

• | The Passlock™ code data CKT 1836 is shorted to voltage for 1 second.

### Action Taken When the DTC Sets

• | The BCM enters the tamper mode.

• | The BCM stores the DTC B2958 in the BCM memory.

• | The vehicle will not start or the vehicle will start and the security indicator will illuminate.

### Conditions for Clearing the MIL/DTC

• | The BCM goes to sleep and reinitializes with the fault cleared.

• | All of the BCM history codes will be cleared after 100 ignition cycles (from OFF to RUN) with no current codes active during the 100 ignition cycles.

• | A Scan Tool is used.

### Diagnostic Aids

• | When the diagnostics direct you to take electrical measurements at the wiring harness junction blocks, refer to Power Distribution Schematics for terminal assignments of the wiring harness junction blocks.

• | If the DTC is a history DTC, the problem may be intermittent. Perform the test shown while wiggling the wiring and connectors. This action often causes the malfunction to appear.

### Test Description

The numbers below refer to the numbers on the diagnostic table.

1. This step determines if a short to the battery exists in CKT 1836 between the BCMand the Passlock® sensor.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open.
1 | Was the Theft Deterrent Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check - Theft Deterrent
2 |

1. Disconnect the body control module (BCM) connector C2.
2. Disconnect the Passlock® sensor connector terminal A.
3. Use the J 39200 in order to measure the voltage in CKT 1836 between the Passlock® connector terminal A and ground.

Is the measured voltage within the specified range?

B+

Go to Step 3

Go to Step 4

3 | Repair the short to B+ in CKT 1836 between the Passlock® connector terminal A and the BCM connector C2 terminal B6. Refer to Wiring Repairs in Wiring Systems Is the repair complete? | -- | Go to Step 12 | --
4 | Use the J 39200 in order to measure the resistance in CKT 1836 between the BCM connector C2 terminal B6 and the Passlock® connector terminal A. Is the measured resistance within the specified range? | 0 - 2ohms | Go to Step 6 | Go to Step 5
5 | Repair the open in CKT 1836 between the BCM connector C2 terminal B6 and the Passlock® connector terminal A. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 12 | --
6 | Inspect for a poor connection at the BCM connector C2 terminal B6. Was a poor connection found? | -- | Go to Step 7 | Go to Step 8
7 | Repair the poor connection at the BCM connector C2 terminal B6. Refer to Wiring Repairs in Wiring Systems Is the repair complete? | -- | Go to Step 12 | --
8 | Inspect for a poor connection at the Passlock® sensor connector terminal A. Was a poor connection found? | -- | Go to Step 9 | Go to Step 10
9 | Repair the poor connection at the Passlock® sensor connector terminal A. Refer to Wiring Repairs in Wiring Systems Is the repair complete? | -- | Go to Step 12 | --
10 |

1. Replace the Passlock® sensor.
2. Reconnect the BCM. Refer to the following procedures:

• | Body Control Module (BCM) Programming/RPO Configuration in Body Control Systems

• | Body Control Module Replacement in Body Control Systems

3. Perform the Reprogramming Procedure Auto Learn.

Is the repair complete?

--

Go to Step 12

Go to Step 11

11 | Replace the BCM. Refer to the following procedures:

• | Body Control Module (BCM) Programming/RPO Configuration in Body Control Systems

• | Body Control Module Replacement in Body Control Systems

Is the repair complete?

--

Go to Step 12

--

12 | Clear the DTCs from the memory. Are the DTCs cleared from the memory. | -- | Go to Diagnostic System Check - Theft Deterrent | --