Loose connection ...
Tokyojoe wrote:
You had a spaceship/UFO hovering directly above you. Don't look up. Not only is it dangerous to take your eyes off the road, the aliens like to play games with us. When humans look up, they zap us with their ray.
Obviously.
On another note, maybe the below will shed some light. A test procedure for the Instrument cluster is provided. I'm assuming that you have not had any check engine lights. This info is provided with a disclaimer from me. I am not a mechanic or employed with DC. I am providing this info for educational purposes only. The material is taken in snippets from an 03 Service manual. If you tear in an instrument cluster, AWAYS disable the air bag circuitry and disconnect the ground terminal of the battery. After all is said and done, if you still have speedometer problems and no check engine light, try disconnecting the battery ground to reset the CPU and see if that changes anything. Of course, if you reset the CPU, it will have to relearn your driving habits over a period of time. Good Luck.
The speedometer gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The speedometer is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the On or Start positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the Off position. The instrument cluster circuitry controls the gauge needle position and provides the following features:
Vehicle Speed Message - Each time the cluster receives a vehicle speed message from the PCM it will calculate the correct vehicle speed reading and position the gauge needle at that speed position on the gauge scale. The cluster will receive a new vehicle speed message and reposition the gauge pointer accordingly about every 86 milliseconds. The gauge needle will continue to be positioned at the actual vehicle speed position on the gauge scale until the ignition switch is turned to the Off position.
Communication Error - If the cluster fails to receive a speedometer message, it will hold the gauge needle at the last indication for about six seconds, or until the ignition switch is turned to the Off position, whichever occurs first. After six seconds, the gauge needle will return to the left end of the gauge scale.
Actuator Test - Each time the cluster is put through the actuator test, the speedometer needle will be swept to several calibration points on the gauge scale in a prescribed sequence in order to confirm the functionality of the gauge and the cluster control circuitry.
The instrument cluster actuator test will put the instrument cluster into its self-diagnostic mode. In this mode the instrument cluster can perform a selfdiagnostic test that will confirm that the instrument cluster circuitry, the gauges, the PCI data bus message controlled indicators, and the chime tone generator are capable of operating as designed. During the actuator test the instrument cluster circuitry will sound the audible tone generator, position each of the gauge needles at various calibration points, illuminate each of the segments in the Vacuum-Fluorescent Display (VFD), and turn all of the PCI data bus message-controlled indicators on and off again. Successful completion of the actuator test will confirm that the instrument cluster is operational. However, there may still be a problem with the PCI data bus, the Powertrain Control Module (PCM), the Airbag Control Module (ACM), the Body Control Module (BCM), the Sentry Key Immobilizer Module (SKIM), or the inputs to one of these electronic control modules.
Use a DRBIIIt scan tool to diagnose these components. Refer to the appropriate diagnostic information.
(1) Begin the test with the ignition switch in the Off position.
(2) Depress the odometer/trip odometer switch button.
(3) While still holding the odometer/trip odometer switch button depressed, turn the ignition switch to the On position, but do not start the engine.
(4) Release the odometer/trip odometer switch button.
(5) The instrument cluster will automatically begin the actuator test sequence, as follows:
(a) The cluster will turn on, then off again each of the PCI data bus message controlled indicators to confirm the functionality of the indicator and the cluster control circuitry:
(b) The cluster will sweep the needles for each of the gauges to several calibration points in sequence to confirm the functionality of the gauge and the cluster control circuitry:
(c) The cluster will sequentially step the odometer/trip odometer VFD display from all ones (111111) through all nines (999999) to confirm the functionality of all VFD segments and their control circuitry, then display the software version number.
(d) The cluster will generate five (5) chime tones to confirm the functionality of the audible tone generator and the control circuitry.
(6) The actuator test is now completed. The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test, if the ignition switch is turned to the Off position during the test, or if an engine rpm message indicating that the engine is running is received from the PCM over the PCI data bus during the test.
(7) Go back to Step 1 to repeat the test, if required.
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- 2003 Jeep Liberty Sport 4X4 -
245/70R16 Revos on Rubicon (Moab) wheels. 2" Revtek spacer lift front. 2.5" Daystar puck rear. Stock struts. Rancho RSX 17004 shocks. Debadged.
http://www.cardomain.com/ride/2104014
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