|91 5.7L VIN 7 TBI
||Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds.
||Coolant temperature sensor signal indicates a temperature of over 275°
F for 2 seconds.
||Coolant temperature sensor signal indicates a temperature colder than
-27° F for 30 seconds after the engine has been running for at least 30
||TPS voltage was above 2.5 volts for 8 seconds when the MAP sensor signal
showed manifold vacuum to be 15 pounds or more.
||TPS voltage was under 0.2 volts for 2 seconds when the engine was running.
||Inlet air temperature sensor signal showed an air temperature below -22°
F after the engine has been running for 5 minutes.
||When engine speed was between 1200 and 4400 RPM and throttle position
angle was less than 2%, the MAP signal showed low voltage (high manifold
vacuum) for at least 5 seconds.
||Inlet air temperature sensor signal showed an air temperature over 302°
F after the engine has been running for 5 minutes. On Fleetwood the inlet
air temperature signal shows a temperature above 297° F for 5 seconds at
a speed less than 35 MPH.
||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.
||MAP sensor signal voltage was too high (low vacuum) for 5 seconds when
throttle opening was under 4%.
||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%.
||The EST signal did not change when the ECM applied bypass voltage to the
||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.
||Oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop
||Oxygen sensor voltage was over 0.7 volts for 30 seconds of closed loop
operation with a throttle angle between 2% and 20%.
||Fuel pump voltage was not present at fuel pump sense line for 2 seconds
after the ECM has sent the fuel pump on command.
||ECM error. Replace ECM.