SELF-DIAGNOSTIC TEST
The instrument cluster self-diagnostic test will put
the instrument cluster into its self-diagnostic mode.
In this mode the instrument cluster can perform a
self-diagnostic test that will confirm that the instru-
ment cluster circuitry, the gauges, and the CCD data
bus message-controlled indicator lamps are capable
of operating as designed.
However, there may still be a problem with the
CCD data bus, the Powertrain Control Module
(PCM), the Transmission Control Module (TCM), the
Airbag Control Module (ACM), the Controller Anti-
lock Brake (CAB), or the inputs to one of these elec-
tronic control modules. Use a DRBIIIt scan tool and
the proper Diagnostic Procedures manual for testing
of these components.
(1) Begin the test with the ignition switch in the
Off position.
(2) Depress the trip odometer reset button.
(3) While holding the trip odometer reset button
depressed, turn the ignition switch to the On posi-
tion, but do not start the engine.
(4) Keep the trip odometer reset button depressed
for about ten seconds, until CHEC appears in the
odometer display, then release the odometer reset
button.
(5) A series of three-digit numeric failure messages
may appear in the odometer display, depending upon
the failure mode. If a failure message appears, see
the Instrument Cluster Failure Message chart for the
description and proper correction. If no failure mes-
sage appears, the self-diagnostic test will proceed as
described in Step 6.
INSTRUMENT CLUSTER FAILURE MESSAGE
Message Description Correction
110 A failure has been identified in the cluster
CPU, RAM, or EEPROM.
1. Replace the faulty cluster.
900 The CCD data bus is not operational. 1. Check the CCD data bus connections at the
cluster.
2. Check the cluster fuses.
3. Check the CCD data bus bias.
4. Check the CCD data bus voltage.
5. Check the CCD data bus terminations.
920 The cluster is not receiving a vehicle speed
message from the PCM.
1. Check the PCM software level and reflash if
required.
2. Use a DRBIIIT scan tool to verify that the
vehicle speed message is being sent by the
PCM.
921 The cluster is not receiving a distance pulse
message from the PCM.
1. Check the PCM software level and reflash if
required.
2. Use a DRBIIIT scan tool to verify that the
distance pulse message is being sent by the
PCM.
940 The cluster is not receiving an airbag lamp-on
message from the ACM.
1. Check the CCD data bus connections at the
ACM.
2. Check the ACM fuse.
950 The cluster is not receiving an ABS lamp-on
message from the CAB.
1. Check the CCD data bus connections at the
CAB.
2. Check the CAB fuse.
960 The cluster is not receiving a PRND21
message from the TCM.
1. Check the CCD data bus connections at the
TCM.
2. Check the TCM fuse.
999 An error has been discovered. 1. Record the failure message.
2. Depress the trip odometer reset button to
continue the Self-Diagnostic Test.
DN INSTRUMENT PANEL SYSTEMS 8E - 7
DIAGNOSIS AND TESTING (Continued)
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