For 1990-2009 cars
Body Control Module Components
Body Control System Schematics

### Circuit Description

CKT 80 is an input to the body control module (BCM). The BCM monitors CKT 80 in order to determine if the ignition switch is in the ON position.

### Conditions for Setting the DTC

All of the following conditions must be met:

• | The key-in input is not active.

• | Ignition 0 is active for 20 seconds.

### Action Taken When the DTC Sets

Stores DTC B2965 in the BCM memory.

### Conditions for Clearing the DTC

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

• | All the BCM history codes clear after 100 ignition cycles (from OFF to ON) with no current codes active during the 100 ignition cycles.

• | Use the Scan Tool in order to read the DTCs.

### Diagnostic Aids

• | Inspect the wiring and connections to the ignition switch.

• | If the DTC is a history DTC, the problem may be intermittent. Perform the above tests while wiggling the wiring and connectors. This may often cause the malfunction to appear.

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 Body Control Module (BCM) System Check performed? | -- | Go to Step 2 | Go to Body Control Module System Check
2 |

1. Locate connector C2 terminal B12 at the BCM.
2. Remove the key from the ignition cylinder.
3. Using J 39200 DMM, backprobe connector C2 terminal B12 for voltage.

Is the measured voltage equal to the specified value

B+

Go to Step 4

Go to Step 3

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

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

• | BCM Replacement.

Is the repair complete?

--

Go to Body Control Module System Check

--

4 |

1. Locate connector C2 terminal B12 at the BCM.
2. Using a scan tool in the BCM inputs menu, read the KEY IN IGNITION screen.
3. Use a fused jumper in order to ground CKT 80 at connector C2 terminal B12 of the BCM.

Does the scan tool BCM inputs menu read KEY IN IGNITION - YES?

--

Go to Step 5

Go to Step 3

5 |

1. Remove connector C2 terminal B12 at the BCM and remove connector C1 terminal D at the ignition switch.
2. Using J 39200 DMM, test the resistance on CKT 80.

Is the measured resistance within the specified range?

0-2 ohms

Go to Step 7

Go to Step 6

6 | Repair the open in CKT 80. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 11 | --
7 |

1. Disconnect connector C1 terminal D and disconnect connector C2 terminal E from the ignition switch.
2. Using J 39200 DMM, measure the resistance in the key warning switch.
3. Install the meter leads on terminal D and terminal E of the ignition switch. Set the meter on continuity. Insert the key into the lock.

Is the measured resistance within the specified values?

0-2 ohms

Go to Step 9

Go to Step 8

8 | Replace the ignition switch lock assembly. Is the repair complete? | -- | Go to Step 11 | --
9 |

1. Disconnect the connector C1 terminal D at the ignition switch and at the ground splice pack G202 terminal D.
2. Using J 39200 DMM, measure the resistance on CKT 151.

Is the measured resistance within the specified values?

0-2 ohms

Go to Step 11

Go to Step 10

10 | Repair the open in CKT 151. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 11 | --
11 | Clear the DTCs from the memory. Are the DTCs cleared from the memory? | -- | Go to Body Control Module System Check | --