P0052

Diagnostic Chart:

Schematic:

The front oxygen sensors are equipped with heaters to assist in ramping up to the nominal operating temperature of the front oxygen sensors. This decreases the amount of time required to enter closed-loop operation where maximum fuel efficiency is attained. The ECM diagnoses the heater and its related wiring by continuously monitoring electrical current. The ECM will set this DTC when the signal being received is too high.

DTC PARAMETERS
This DTC will set when:
^ Heater voltage is greater than 3.6 volts
^ Engine is running
^ Above conditions have been met for 50 ms

DTC P0052 is a (type B) DTC

DIAGNOSTIC AIDS
To locate an intermittent problem use Scan tool to monitor the HO2S Heater Bn 2 Sen. 1 voltage with engine idling at normal operating temperature.

Wiggling wires while monitoring HO2S Heater Bn 2 Sen. 1 voltage may locate area where short to voltage exists.

Review failure record information to check if vehicle was running rich in decel (TP angle equals zero percent HO2S Bank 2 Sensor 1 reading less than 0.8) when DTC was set. If so, check for possible rich condition.