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John, GMC Technician
Category: GM
Satisfied Customers: 9176
Experience:  ASE MASTER TECHNICIAN/40 years experience
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2004 Chevy Impala: fuel gauge..temp gauge..Instrument cluster or BCM

Customer Question

2004 Chevy Impala 3.4 fuel gauge and temp gauge dont work. Instrument cluster or BCM? If BCM how do you test it?
Submitted: 6 years ago.
Category: GM
Expert:  John replied 6 years ago.

Hello & Welcome to JA,


This problem is usually the instrument cluster or PCM. You will teat the circuit before condemning the PCM. Use a scan tool to verify coolant & fuel gage data , compare to cluster. If it looks good at the PCM the problem is most likely the cluster. Test the wiring from the PCM to the cluster for a good circuit. Here is a schematic to help.


Object Number:(NNN) NNN-NNNN Size: FS

Customer: replied 6 years ago.
PCM not BCM? Where is the PCM?
Expert:  John replied 6 years ago.
The PCM is located

Left side of the engine compartment, forward of the strut tower, inside the air filter box


Object Number:(NNN) NNN-NNNN Size: LF

(1)Air Cleaner/PCM Housing
(2)A/C Refrigerant Pressure Sensor
(3)Powertrain Control Module (PCM), C2
(4)Powertrain Control Module (PCM), C1
(5)Powertrain Control Module (PCM)