GM Service Manual Online
For 1990-2009 cars only

Object Number: 284890  Size: MF
Body Control Module Components
Cell 51: Ign Switch and Left Front Door Ajar Switch

Circuit Description

This circuit controls the front foglamp relay coil by grounding the circuit through the body control module (BCM). This is a fault code (both history and current) that gets set when the front foglamp relay output is currently shorted to battery.

Conditions for Setting the DTC

All of the following conditions must be met:

    • The parklamps are commanded on by either the automatic light control (ALC) function or manually.
    • The front foglamp option is enabled within the BCM.
    • Ignition one is active.
    • The front fog lamp relay output is on.

Action Taken When the DTC Sets

    • Turns off the front foglamp relay.
    • Stores the DTC B2533 in the BCM memory.

Conditions for Clearing the DTC

    • The fault state is exited upon the program return to the front foglamp relay OFF state.
    • The BCM goes to sleep and reinitializes with the fault cleared.
    • All 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.
    • Use the Scan Tool .

Diagnostic Aids

    • When the diagnostics direct you to take electrical measurements at the junction blocks, refer to Power Distribution Schematics in Wiring Systems for terminal assignments of the junction blocks.
    • If the DTC is a history DTC, the problem may be intermittent. Try performing the above tests while wiggling the wiring and connectors. This can often cause the malfunction to appear.

Test Description

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

  1. This step verifies proper operation of the front fog lamp relay.

  2. This step determines if an open exists in CKT 1317 within the right IP wiring harness junction block.

  3. This step determines if a short to battery exists in CKT 1317 between the body control module (BCM) and the right IP wiring harness junction block.

Step

Action

Value(s)

Yes

No

1

Was the BCM system check performed?

--

Go to Step 2

Go to the Body Control Module System Check

2

  1. Replace the front foglamp relay with a known good relay on the right IP junction block.
  2. Use the Scan Tool in order to enable the front foglamp relay.

Did the front foglamp relay activate?

--

Go to Step 8

Go to Step 3

3

  1. Remove the front foglamp relay on the right IP junction block.
  2. Back out the right IP junction block connector C1 terminal F3 CKT 1317.
  3. Use the J 39200 DMM in order to measure the voltage in CKT 1317 between the right IP junction block connector C1 terminal F3 and ground.

Is the measured voltage at the specified value?

0 V

Go to Step 5

Go to Step 4

4

Replace the right IP junction block. Refer to Relay/Fuse Center Replacement in Wiring Systems.

Is the repair complete?

--

Go to Step 8

--

5

  1. Disconnect the BCM connector C1
  2. Use the J 39200 DMM in order to measure the voltage in CKT 1317 between the right IP junction block harness connector C1 terminal F3 and ground.

Is the measured voltage at the specified value?

0 V

Go to Step 6

Go to Step 7

6

Replace the BCM. Refer to the following procedures:

Is the repair complete?

--

Go to Step 8

--

7

Repair the short to B+ in CKT 1317 between the BCM connector C1 terminal A2 and the right IP junction block harness connector C1 terminal F3. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 8

--

8

Clear the DTCs from the memory.

Are the DTCs cleared from the memory?

--

Go to the Body Control Module System Check

--