GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Malibu 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC B2588 Parklamp Relay Output Short to Battery

Object Number: 399500 Size: MF
Body Control Module Components
Cell 51: SDM, Washer Solvent Lever Sensor, Seat Belt Switch and Park Brake Switch

Circuit Description

This is a trouble code (both current and history) that indicates the ALC parklamp relay control output is shorted to the battery.

Conditions for Setting the DTC

All of the following conditions must be met:

    • The ignition switch is in the RUN position.
    • The ALC option is enabled.
    • The ALC parklamp output is active.
    • The ALC parklamp feedback is not present for one second.

Action Taken When the DTC Sets
    • Turns OFF the ALC parklamp
    • Enters a fault state
    • Stores DTC B2588 in the body control module (BCM) memory
    • The SERVICE VEHICLE SOON indicator will illuminate.

Conditions for Clearing the DTC
    • The fault state is exited upon the program return to the ALC parklamp OFF state.
    • 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.
    • Use the scan tool.

Diagnostic Aids

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.

Test Description

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

  1. This step determines if the ALC parklamp relay is operating properly.

    2.

  2. This step determines if there is a short to the battery in CKT 1080 within the underhood wiring harness junction block.

    3.

  3. This step determines if there is a short to the battery in CKT 1080 between the body control module (BCM) and the underhood wiring harness junction block.

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 BCM System Check performed?

--

Go to Step 2

Go to Body Control Module System Check

2

  1. Replace the ALC parklamp relay with a known good relay on the underhood wiring harness junction block.
  2. Use the scan tool in order to enable the ALC parklamp relay.

Did the ALC parklamp relay activate?

--

Go to Step 8

Go to Step 3

3

  1. Remove the ALC parklamp relay on the underhood wiring harness junction blocks.
  2. Backprobe the underhood wiring harness junction block connector C3 terminal B8.
  3. Use the Digital Multi Meter in order to measure the voltage in CKT 1080 between the underhood wiring harness junction block connector C3 terminal B8 and ground.

Does the measured voltage equal the specified value?

0 V

Go to Step 5

Go to Step 4

4

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

Is the repair complete?

--

Go to Step 8

--

5

  1. Disconnect the BCM connector C1.
  2. Use the J 39200 Digital Multi Meter in order to measure the voltage in CKT 1080 between the underhood wiring harness junction block harness connector C3 terminal B8 and ground.

Does the measured voltage equal 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 1080 between the BCM connector C1 terminal B1 and the underhood wiring harness junction block harness connector C3 terminal B8. 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 Body Control Module System Check

--