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Code 45: Rich Exhaust Indication: Notes

CODE 45 ECM TERMINAL & CIRCUIT WIRING IDENTIFICATION

Application ECM Terminal Wire Color
O2 Signal J1D09 Purple
O2 Ground J1D10 Tan

O2 sensor acts like an open sensor circuit and produces no voltage when exhaust temperature is less than 600°F (316°C). An open sensor circuit or cold sensor causes "open loop" operation.

Code 45 indicates a rich exhaust. Diagnosis should begin with fuel pressure, leaking injector, HEI shielding (ground), vapor canister fuel saturation, coolant sensor, MAP sensor, O2 sensor contamination and TPS intermittent output.

NOTE: Test number refers to number on diagnostic chart.
  1. Test checks to see if O2 sensor is registering a rich condition. Code 45 is set when vehicle is at operating temperature (in "closed loop"), throttle angle is greater than idle, O2 sensor signal at control module is greater than .7 volt for a precalibrated period and time since engine start is one minute or more.