2010 Cadillac CTS Sedan AWD V6-3.6L Page 873

2010 Cadillac CTS Sedan AWD V6-3.6L Page 873

- HO2S Slow Response Rich to Lean Bank 1 Sensor 2

DTC P013C

- HO2S Slow Response Rich to Lean Bank 2 Sensor 2

DTC P013E

- HO2S Delayed Response Rich to Lean Bank 1 Sensor 2

DTC P014A

- HO2S Delayed Response Rich to Lean Bank 2 Sensor 2

Diagnostic Fault Information

Circuit Description

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding

air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the

HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450

mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above

and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control

module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a

rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed

Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

Conditions for Running the DTCs

* Before the ECM can reports that DTC P013A, P013C, P013E, or P014A failed, DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0135,

and P0155 must run and pass.

* DTC P0036, P0037, P0038, P056, P0057, P0058, P0137, P0138, P0140, P0141, P0157, P0158, P0160, P0161, P0300, P0301, P0302, P0303,

P0304, P0305, P0306, P0442, P0443, P0455, P0458, P0459, P2096, P2097, P2098, P2099, P2177, P2178, P2179, P2088, P2089, P2090,

P2232, P2235, P2270, P2271, P2272, or P2273 is not set.

* The ignition voltage is greater than 10 volts.

* The HO2S 1 and 2 are in closed loop.

* The HO2S 2 resistance is less than 900 ohms.

* The HO2S 2 has switched from lean to rich during the ignition cycle.

* The calculated exhaust gas mass flow rate is greater than 2.22 g/s.

* The calculated exhaust gas temperature for HO2S 2 is warmer than 450掳C (842掳F).

* The HO2S 1 signal voltage is less than 141 mV

* The HO2S 2 signal voltage is greater than 590 mV at the beginning of decel fuel cut-off - DTC P013E and P014A only.

* The DTCs run continuously once the conditions above exist for greater than 4 seconds.

Conditions for Setting the DTCs

P013A or P013C

The ECM determines that the response time for the HO2S 2 to switch from greater than 400 mV to less than 200 mV is greater than 800 mS. The

condition exists for greater than 4 seconds or for a cumulative time of 30 seconds.

P013E or P014A

* The ECM determines the time for the HO2S 2 to transition from greater than 590 mV to less than 140 mV, during decel fuel cut-off is greater

than 4 seconds. The condition exists for greater than 4 seconds or for a cumulative time of 30 seconds.

OR

* The ECM determines that the air flow into the engine exceeded 15 grams before the HO2S 2 transitions to less than 140 mV, during decel

fuel cut-off. The condition exists for greater than 4 seconds or for a cumulative time of 30 seconds.

Action Taken when the DTCs Set

DTCs P013A, P013C, P013E, and P014A are Type B DTCs.