List of engine diagnostic codes provided by the On-Board Diagnostic (ODB).
Applies to 350cui VIN K 1988-1990
- 13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds
- 14 Coolant temperature sensor signal indicates a temperature of over 275° F for 2 seconds
- 15 Coolant temperature sensor signal indicates a temperature colder than -27° F for 30 seconds after the engine has been running for at least 30 seconds
- 21 TPS voltage was above 2.5 volts for 8 seconds when the MAP sensor signal showed manifold vacuum to be 15 pounds or more
- 22 TPS voltage was under 0.2 volts for 2 seconds when the engine was running
- 23 Inlet air temperature sensor signal showed an air temperature below -22° F after the engine has been running for 5 minutes
- 24 Vehicle Speed Sensor (VSS) Circuit
- 25 Inlet air temperature sensor signal showed an air temperature over 302° F after the engine has been running for 5 minutes
- 32 EGR open command did not change MAP sensor signal. Normal EGR flow should cause slight decrease in manifold vacuum which would change MAP sensor signal
- 33 MAP sensor signal voltage was too high (low vacuum) for 5 seconds when throttle opening was under 4%
- 34 MAP sensor signal voltage was too low (high vacuum) when engine speed was under 1200 RPM or the engine speed was over 1200 RPM with a throttle position angle above 21%
- 35 Idle Air Control (IAC) System
- 42 The EST signal did not change when the ECM applied bypass voltage to the ignition module
- 43 The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194° F or the knock signal was present for 5 seconds or more during normal engine operation. Electronic Spark Control (ESC) Circuit
- 44 Oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation (Lean Exhaust Indicated)
- 45 Oxygen sensor voltage was over 0.7 volts for 30 seconds of closed loop operation with a throttle angle between 2% and 20% (Rich Exhaust Indicated)
- 51 PROM error. (MEM-CAL)
- 52 CALPAK error. Fuel CALPAK Missing
- 53 System Over Voltage
- 54 Fuel pump voltage was not present at fuel pump sense line for 2 seconds after the ECM has sent the fuel pump on command (Low Voltage)
- 55 ECM error. Replace ECM. Faulty ECM
