|90-91 3.1L VIN V MFI
||Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds
when the TPS signal was above 4%. The engine had been running for at least
||Coolant temperature sensor signal indicates a temperature of over 275°
F for 3 seconds.
||Coolant temperature sensor signal indicates a temperature colder than
-38° F for at least 20 seconds.
||TPS voltage was above 4.3 volts for 10 seconds when engine was running
and air flow was less than 17 gm/sec.
||TPS voltage was under 0.25 volts for 4 seconds when the ignition was on.
||Manifold air temperature sensor signal showed an air temperature of -31°
F for 10 seconds after engine had been running for 4 minutes.
||Engine speed was between 2200 and 4400 RPM and transmission was not in
park or neutral and TPS was less than 2% for 3 seconds.
||Manifold air temperature sensor signal showed an air temperature over
293° F for 3 seconds when vehicle speed was greater than 3 MPH and engine
had been running for 8 minutes.
||Quad-driver sense voltage showed a low voltage when battery voltage should
be present, or the sense voltage showed battery voltage when a low voltage
should be present.
||The ECM opens each EGR control valve during deceleration and monitors
the change in manifold vacuum. The code sets when the change in manifold
vacuum is outside the normal range.
||MAP sensor voltage was too high for 4.8 seconds when throttle angle was
less than 2%.
||MAP sensor voltage was too low for 1 second when engine speed was under
600 RPM, or MAP sensor voltage was too low for 1 second when engine speed
was over 600 RPM and throttle angle was above 20%.
||Engine idle speed is either 300 RPM above or below the desired idle speed
for 50 seconds.
||Faulty or incorrect MEM-CAL.
||The EST signal did not change when the ECM applied bypass voltage to the
||Knock sensor signal was either above 3.5 volts or below 1.5 volts for
at least 0.5 seconds.
||Oxygen sensor voltage was under 0.2 volts for at least 60 seconds of closed
||Oxygen sensor voltage was over 0.7 volts for 50 seconds in closed loop
operation with a throttle angle between 3% and 45%.
||ECM sees a battery voltage of more than 17.1 volts for 2 seconds.
||Fuel pump voltage was less than 4 volts for 0.4 seconds.
||Vehicle gear commanded by ECM did not match actual gear selected.
||A/C pressure sensor voltage was either above 4.9 volts or below 0.1 volts
for at least 5 seconds.