DTC 13

Fig. 032 Chart - Code 13 Open Oxygen Sensor Circuit:

Fig. 033 - Wiring Diagram for Code 13 Open Oxygen Sensor Circuit. VIN P:

CODE 13

OPEN OXYGEN SENSOR CIRCUIT

2.0L ENGINE

FUEL INJECTION (TBI)

Code 13 WILL SET, if all of these condition are met:
a. At least 2 minutes engine time after start.
b. O2 signal voltage steady between .35 and .55 volts for more than one minute.
c. Engine Speed above 2000 RPM.
d. Engine coolant temperature above 70°C (158°F).
The ECM supplies a voltage of about .45 volt between terminals "D6" and "D7". (If measured with a 10 megohm digital voltmeter, this may read as low as .32 volts). The O2 sensor varies the voltage within a range of about 1 volt if the exhaust is rich, down through about.10 volt if exhaust is lean.
The sensor is like an open circuit and produces no voltage when it is below 360°C (600°F). An open sensor circuit or cold sensor causes "open loop" operation.
1. Grounding the diagnostic terminal with the engine running enables the "Field Service Mode", which allows the ECM to confirm either open or closed loop operation using the "SERVICE ENGINE SOON" light.
2. This step simulates a lean exhaust. If the ECM and wiring are OK the ECM will see the lean condition and turn the "SERVICE ENGINE SOON" light off for at least 15 seconds after engine start, and then flash "open loop". It should be considered normal if the light remains off for a longer period of time before flashing "open loop".