Speedometer Gauge Not Operating Properly

Possible Causes:

• Attempt To Communicate With The PCM
• Engine Trouble Codes
• Instrument Cluster Self Test
• Observe The Vehicle Speed Display In The PCM
• Observe The Vehicle Speed Display In The Instrument Cluster
• Powertrain Control Module

Testing

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, attempt to communicate with Powertrain Control Module (PCM). If scan tool communicates with PCM, go to next step. If scan tool does not communicate with PCM, perform NO RESPONSE FROM PCM (PCI BUS)  test under COMMUNICATION SYSTEMS.
2. Turn ignition off. To start gauges self-test, press and hold trip button on instrument cluster while turning ignition switch forward one position from LOCK to OFF position, then release trip button. If speedometer sweeps from zero MPH to 120 MPH then back to zero MPH, go to next step. If speedometer does not sweep from zero MPH to 120 MPH then back to zero MPH, replace instrument cluster. See ANALOG INSTRUMENT PANELS - CONCORDE, INTREPID & 300M article.
3. Using scan tool, retrieve PCM DTCs. If any PCM DTCs exist, see SELF-DIAGNOSTICS - CONCORDE, INTREPID & 300M article in ENGINE PERFORMANCE. If no PCM DTCs exist, go to next step.
4. Raise and support vehicle. Start engine. Turn traction control off (if equipped). Using scan tool in ENGINE SENSORS, monitor VEHICLE SPEED. Place gear shift lever in Drive and accelerate vehicle. If vehicle speed increases on display, go to next step. If vehicle speed does not increase on display, repair vehicle speed signal as necessary. See SELF-DIAGNOSTICS - CONCORDE, INTREPID & 300M article in ENGINE PERFORMANCE.
5. Using scan tool in ELECTRO/MECH CLUSTER, monitor VEHICLE SPEED. Accelerate vehicle. If vehicle speed increases on display, replace instrument cluster. See ANALOG INSTRUMENT PANELS - CONCORDE, INTREPID & 300M article. If vehicle speed does not increase on display, replace PCM. See POWERTRAIN CONTROL MODULE  under REMOVAL & INSTALLATION.