DTC 45

- Chart - Code 45 Rich Exhaust Indication.:

- Wiring Diagram for Code 45 Rich Exhaust Indication.:

CODE 45, RICH EXHAUST INDICATION

CIRCUIT DESCRIPTION
Code 45 says that the ECM has seen:
a. High oxygen sensor voltage
b. More than specified time (about 2 minutes)
c. Above a specified TPS value
d. Closed loop
A high voltage can be caused by a rich exhaust or O2 sensor contaminated with silicone.

CHART DESCRIPTION
1. Checks to see if fault is still present. A dwell of under 50° indicates engine should be checked for cause of intermittent rich condition: i.e.,
a. Purge or bowl vent valves leaking.
b. Fuel in crankcase.
c. Fuel in evaporative canister.
d. Sticking mixture control solenoid or metering rods.

2. This step causes a lean condition by putting an air leak into the engine to see if ECM can respond. A drop in the dwell indicates ECM and O2 sensor are not faulty. Look for source of constant rich condition. See step one examples.
3. This step tests to see if ECM is able to respond to a lean exhaust O2 signal (low voltage). If no dwell change with a grounded lead to O2 sensor Term. "9", fault is in ECM. It couldn't be an open O2 wire because that would set Code 13.
4. This step checks the voltage from the ECM at the O2 sensor harness. Normal voltage at this point is the ECM bias voltage for no O2 signal which is approximately .45V. If voltage is high, the wire to the ECM could be shorted to B+, or it is a faulty ECM.