What to do next....?

Asked by Jun 07, 2014 at 03:50 PM about the Chevrolet Silverado 1500

Question type: Maintenance & Repair

I have a 1988 Chevy Silverado 1500 5.7L V8, It idles really high and won't pass emissions.  We replaced the Idle Air Control Valve and hooked up to the computer and received the following codes:
31-Cam Position Sensor Fault
32-EGR Circuit Fault
33-MAP Sensor Signal Out of Range (High)
35-Idle Air Control Sensor Fault Circuit
51-Calabration Error, MEM Cal, ECM or EEPROM Failure
52-Engine Oil Temp Circuit, Low Temp Indicated
54-EGR System Failure or Fuel Pump Circuit Low Voltage
55-A/D Converter Error or PCM Not Grounded or Lean Fuel or Frounder Reference Voltage

Trying to figure out if we should replace ALL the sensors or if one bad one would cause the rest.  Not sure what to do, any advice would be greatly appreciated.

1 Answer


I'd go after the ECM first. Sounds like the PROM is either installed wrong or bad. Could also be the ECM itself. If the ECM and/or PROM is bad it can cause all sorts of crazy things to happen. Ignore the other trouble codes until you're sure that the ECM and PROM are good. HTH. -Jim

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