Dash gauge Problem with my 2004 Chevy Trailblazer
4.2 six cylinder
ABS, seatbelt, battery, parking brake lights
GM Computer codes none
Repairs done prior = Installed aftermarket radio 4-5 months before problem
Repairs for this problem = rebuilt instrument panel cluster
GM tech = JK
question = All gauges in IPC are bottomed out except tach and speedo. ABS,seatbelt,battery,
and parking brake lights constantly stay on.
Cruise control works, but indicator light saying I am in cruise doesn't appear.
Also, the gear indicator light telling me if I am in P,R,N,etc.. Doesn't highlight the gear I am in.
Had cluster rebuilt, problem still there.
1st question:
Could you possibly provide me with information that gives a pin out of my IPC harness and the
voltages that should be there.
2nd:
ECU location and the harness that goes to my IPC pin out with voltages.
I didn't make a donation because I wasn't sure if this information is available through this sight,
but I will gladly make one if it is.
JK:
After reading about the different problems with different seemingly unrelated indicators / gauges,
i looked through some schematics.
The thing that stands out is that then tach and speedo signal are given to the IPC from the PCM
from their own, separate circuits. ALL the other indicators get their signal from the PCM, but on a
different circuit. In other words, all indicators are feed from the PCM to the IPC on 1 wire, called
the Class 2 serial data line. The speedo has its own wire, the tach has its own.
First be sure to check ALL fuses. Underhood fuse block, and block under the rear seat.
If all ok, i would suspect either a PCM problem, or more likely a problem with the serial data wire
between the PCM and the IPC.
A continuity check of that circuit is probably your best / next check.
4.2 six cylinder
ABS, seatbelt, battery, parking brake lights
GM Computer codes none
Repairs done prior = Installed aftermarket radio 4-5 months before problem
Repairs for this problem = rebuilt instrument panel cluster
GM tech = JK
question = All gauges in IPC are bottomed out except tach and speedo. ABS,seatbelt,battery,
and parking brake lights constantly stay on.
Cruise control works, but indicator light saying I am in cruise doesn't appear.
Also, the gear indicator light telling me if I am in P,R,N,etc.. Doesn't highlight the gear I am in.
Had cluster rebuilt, problem still there.
1st question:
Could you possibly provide me with information that gives a pin out of my IPC harness and the
voltages that should be there.
2nd:
ECU location and the harness that goes to my IPC pin out with voltages.
I didn't make a donation because I wasn't sure if this information is available through this sight,
but I will gladly make one if it is.
JK:
After reading about the different problems with different seemingly unrelated indicators / gauges,
i looked through some schematics.
The thing that stands out is that then tach and speedo signal are given to the IPC from the PCM
from their own, separate circuits. ALL the other indicators get their signal from the PCM, but on a
different circuit. In other words, all indicators are feed from the PCM to the IPC on 1 wire, called
the Class 2 serial data line. The speedo has its own wire, the tach has its own.
First be sure to check ALL fuses. Underhood fuse block, and block under the rear seat.
If all ok, i would suspect either a PCM problem, or more likely a problem with the serial data wire
between the PCM and the IPC.
A continuity check of that circuit is probably your best / next check.
Question: My husband just acquired a 94 Chevy Silverado C/K 1500. The instrument panel doesn't work properly
at all. The odometer continues running when the truck is parked with engine running and the speedometer shows
120 while we are sitting still in the driveway. He has so far: Replaced the fuses in fuse box, tried a used
replacement cluster and it did the same thing, and no effect. What could be causing this problem? Thank you for
any help you can suggest :) Patricia
at all. The odometer continues running when the truck is parked with engine running and the speedometer shows
120 while we are sitting still in the driveway. He has so far: Replaced the fuses in fuse box, tried a used
replacement cluster and it did the same thing, and no effect. What could be causing this problem? Thank you for
any help you can suggest :) Patricia
Answer: You probably have a shorted out, or faulty vehicle speed
sensor. If it's sending a reading to the instrument cluster, even if the
vehicle is not moving, the speedometer and odometer will keep
registering miles and mph. You can try disconnecting the sensor, which
is located at the rear of the transmission if it is a two wheel drive truck
or at the rear of the transfer case if it a four wheel drive truck. If you
disconnect it and the problem stops, you know the sensor is bad. If the
problem keeps occurring, you have a wiring problem somewhere along
that harness that would need to be checked out.
sensor. If it's sending a reading to the instrument cluster, even if the
vehicle is not moving, the speedometer and odometer will keep
registering miles and mph. You can try disconnecting the sensor, which
is located at the rear of the transmission if it is a two wheel drive truck
or at the rear of the transfer case if it a four wheel drive truck. If you
disconnect it and the problem stops, you know the sensor is bad. If the
problem keeps occurring, you have a wiring problem somewhere along
that harness that would need to be checked out.
