P017

DTC PO17:

Oxygen Sensor Circuit:

DESCRIPTION
The Powertrain Control Module (PCM) provides a 0.45 volt reference to the oxygen sensor on CKT 412. When the oxygen sensor reaches operating temperature it will generate a counter voltage that will vary based on the amount of oxygen in the exhaust. The front oxygen sensor is located in the manifold just behind the cooling fan. A lean exhaust will generate a low voltage and cause the 0.45 reference voltage to move lower. A rich exhaust will generate a high voltage and cause the 0.45 reference voltage to move higher. If the oxygen sensor can't respond under the test conditions and generate a voltage greater or less than the 0.45 reference volts, it will set a Code P017. Possible causes of Code P017 are:

1. Open in CKT 412 or 413.
2. Short to voltage on CKT 412 or 413.
3. Oxygen sensor that cannot respond.

TEST CONDITIONS
1. Codes P014, P015, P021, P022, P026, and P027 not set.
2. Coolant temperature 81.5°C (179°F) or greater.
3. Throttle angle between 5.0 and 29.8 degrees.
4. Throttle position switch open.
5. RPM 800 or greater.

FAILURE CONDITIONS
Oxygen sensor voltage stays between 0.307 volt and 0.609 volt for more than 64 seconds (oxygen sensor voltage not toggling). Code P017 is set.

ACTION TAKEN
1. PCM turns "ON" the "Service Engine Soon" Malfunction Indicator Lamp (MIL).
2. PCM enables evaporative emission control solenoid if Code P013 is also set.
3. "Closed Loop" operation disabled.

NOTES ON FAULT TREE
1. Voltage on PCM data parameter PD32 should fluctuate above 0.6 volt and below 0.3 volt. If voltage remains above 0.6 volt, check CKT 412 for a short to voltage. If voltage remains below 0.3 volt, check CKT 412 for a short to ground.

2. Measuring voltage with a voltmeter will isolate a sensor/wiring problem from a PCM problem. If voltage fluctuates above 0.6 volt and below 0.3 volt, the fault is with the PCM. If voltage remains below 0.3 volt, check CKT 412 for a short to ground or CKT 413 for a short to voltage. If voltage remains above 0.6 volt, check CKT 412 for a short to voltage. If voltage remains between 0.3 volt and 0.6 volt, check CKT 412 and CKT 413 for an open.