How do I DETERMAN WHAT IS WRONG my speedometer and rpm gauges aren't working
a fuse blew.
this car has an electronic dash cluster. (with brain)
first is fuses. (check them first) (2 of them)
second is scan it. scan the PCM for DTC error !
if rpm dies, for sensors the engine dies...
The PCM runs spark and injection off 2 sensor and RPM
if they die so does spark and injection.
the cluster has self test mode, try that first?
this proves the cluster is ok.
this is covered in the FSM for your JEEP
the WJ jeep
Chapter 8J covers all this.. to great details.
fuse 17 and 22 must be good. JB box, cab.
posted now 100 of times, here it is again.
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 electro-luminescent
illumination lamp (if equipped) are capable of
operating as designed. During the actuator test the
instrument cluster circuitry will sweep each of the
gauge needles across the gauge faces, illuminate each
of the segments in the Vacuum-Fluorescent Display
(VFD), turn all of the PCI data bus message-controlled
indicators on and off again, and turn the electro-
luminescent illumination lamp (if equipped) 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, the Airbag Control
Module (ACM), the Body Control Module (BCM),
the Controller Anti-lock Brake (CAB), 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.
If an individual indicator lamp or the electro-luminescent
illumination lamp do not illuminate during
the actuator test, the instrument cluster should be
removed. However, check that the incandescent lamp
bulb is not faulty, that the bulb holder is properly
installed on the instrument cluster electronic circuit
board, or that the electro-luminescent lamp pigtail
wire connector is properly connected to the instrument
cluster electronic circuit board before considering
instrument cluster replacement. If the bulb and
bulb holder, or the electro-luminescent lamp connection
check OK, replace the faulty instrument cluster
(1) Begin the test with the ignition switch in the
(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
(except Airbag) to confirm the functionality of the
indicator and the cluster control circuitry:
(b) The cluster will sweep the needles for each of
the gauges from minimum to maximum and back
to minimum to confirm the functionality of the
gauge and the cluster control circuitry:
(c) Only on models with a premium version of
the cluster, the cluster will illuminate the electroluminescent
lamp and turn it off again to confirm
the functionality of the lamp and the cluster control
(d) The cluster will sequentially step the odometer/
trip odometer VFD display from all zeros
(000000) through all nines (999999) to confirm the
functionality of all VFD segments and their control
circuitry, then display the software version number,
followed by "DONE".
(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 a vehicle
speed message indicating that the vehicle is moving
is received from the PCM over the PCI data bus during
(7) Go back to Step 1 to repeat the test, if
if this passes and fuses are good
then you may have DTC errors scanned
if you scan it and you see comminications error from PCM to cluster, well that be it. ... and am not going into THAT>here.
Aug 18, 2015 |
2004 Jeep Grand Cherokee Overland