GM Service Manual Online
For 1990-2009 cars only

Object Number: 427808  Size: SF

Circuit Description

This code (both current and history) is stored in the body control module (BCM). This code indicates that the instrument cluster has sensed a loss of the serial peripheral interface (SPI) data from the BCM.

Conditions for Setting the DTC

All of the following conditions must be met:

    • Ignition 0 is active.
    • The serial data transmitted from the BCM to the instrument panel cluster (IPC) is incorrect for 12 seconds.

Action Taken When the DTC Sets

    • Stores DTC U2000 in the BCM memory
    • The fuel gauge is at zero.
    • The temperature gauge is at zero.
    • The THEFT SYSTEM, ABS, and SERVICE VEHICLE SOON indicators illuminate.

Conditions for Clearing the DTC

    • The BCM goes to sleep and reinitializes with the malfunction 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

    • Diagnose DTC U2001 BEFORE diagnosing DTC U2000.
    • With the ignition switch in the ON position, test for voltage transmissions on the SPI data line.
    • 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) Diagnostic System Check performed?

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Go to Step 2

Go to Body Control Module System Check

2

Diagnose and repair DTC U2001 through U2007.

Is the repair complete?

--

Go to Step 5

Go to Step 3

3

Use the scan tool in order to check if DTC U2000 is current without any DTCs within DTC U2001 through U2007 as current codes.

Is U2000 a current DTC without any DTCs within DTC U2001 through 2007 as current codes?

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Go to Step 4

Go to Step 2

4

Replace the BCM. Refer to Body Control Module Replacement and Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Is the repair complete?

--

Go to Step 5

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5

Clear the DTCs from the memory.

Are the DTCs cleared from the memory?

--

Go to Body Control Module System Check

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