Non-Turbo

DIAGNOSTIC CHART

Code 45 Diagnostic Chart:

NOTE: If the M/C solenoid does not "click" with ignition "ON," test terminal connected and no code 23, check for sticking solenoid.
If the High Altitude System malfunctions, code 45 will sometimes be stored at VERY high altitudes.


TEST DESCRIPTION

These steps correspond to the numbered steps on the diagnostic chart:

1. Check for possible causes of intermittent rich condition such as:
Purge or bowl vent valves leaking
Fuel in crankcase
Fuel saturated charcoal canister
Sticking mixture control solenoid

2. This simulates a lean condition to check ECM response. A drop in dwell indicates that the ECM and oxygen sensor are okay.

3. Checks to see if ECM responds to a lean oxygen sensor signal (low voltage).

4. This step checks the voltage from the ECM at the oxygen sensor harness. Normal voltage at this point is ECM bias voltage for no oxygen sensor signal. It is approximately .45V. If voltage is high, the wire to the ECM could be shorted to B+ or the ECM is faulty.

5. This step differentiates between an open or short in the wire from the oxygen sensor connector to ECM terminal "3" or a faulty ECM.