Diagnostic Aids
Using ED20 display, observe block learn values at different RPM and airflow conditions. If conditions for Code E045 exist, block learn values will be around 115. Check for the following conditions:
- Fuel Pressure. System will go rich if pressure is too high. ECM can compensate for some increase in fuel pressure. If fuel pressure becomes too high, a Code E045 may be set.
- Rich Injector. Perform injector balance test, see SYSTEM/COMP TESTS article.
- Canister Purge. Check for fuel saturation. If full of fuel, check canister control and hoses.
- MAF Sensor. An output that causes ECM to sense a higher than normal air flow can cause system to go rich. Unplugging MAF sensor will allow ECM to set a fixed value for sensor. Substitute a different MAF sensor if rich condition is rectified while sensor is unplugged.
- Fuel. Check for leaking fuel pressure regulator diaphragm by checking vacuum line to regulator for raw fuel. Check for contaminated fuel.
- TPS. An intermittent TPS output will cause system to go rich, due to a false indication of engine acceleration.
- EGR. An EGR staying open (especially at idle) will cause the O2 sensor to indicate a rich exhaust, and could result in a Code E045.