Instrument Cluster Test 3B - Speedometer Not Operating Properly
NOTE:
Perform INSTRUMENT CLUSTER TEST 1A
before proceeding with this test. For connector terminal ID, see CONNECTOR IDENTIFICATION
and WIRING DIAGRAMS
. Perform TEST VER-1A - VERIFICATION PROCEDURE
after each repair.
CAUTION:
Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.
- Using scan tool, read engine trouble codes. If codes related to Vehicle Speed Sensor (VSS) are displayed, see TESTS W/CODES article in the ENGINE PERFORMANCE section. If no VSS codes are displayed, go to next step.
- Using scan tool, actuate instrument cluster gauges. Speedometer should move to 100 MPH mark, then in steps should move to 75, 55, 20, zero MPH marks. If speedometer functions as described, replace Body Control Module (BCM). See Figure in CHIME TEST 3A. If speedometer does not function correctly, go to next step.
- Remove instrument cluster and access back of gauges. Using external ohmmeter, measure resistance diagonally across speedometer terminals. If resistance is 200-220 ohms, replace instrument cluster circuit board. If resistance is not 200-220 ohms, replace speedometer gauge pack.