2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1095
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 DTC
DTC P0131 - Condition 1
* DTC P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or
P0277 is not set.
* The ignition voltage is greater than 11 volts.
* The engine is operating.
* The air flow into the engine is greater than 10 grams.
* The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
* DTC P0131 runs continuously once the conditions above exist for greater than 30 seconds.
DTC P0131 - Condition 2
* DTC P0116, P0117, P0118, P0119, P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270,
P0271, P0273, P0274, P0276, or P0277 is not set.
* The ignition voltage is greater than 11 volts.
* The engine is operating for greater than 1 second.
* The engine coolant temperature (ECT) during the previous ignition cycle was greater than 60掳C (140掳F).
* The ECT at start-up is less than 40掳C (104掳F).
* The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
* DTC P0131 runs continuously once the conditions above exist.
DTC P0132
* DTC P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or
P0277 is not set.
* The ignition voltage is greater than 10 volts.
* The engine is operating.
* The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
* DTC P0132 runs continuously once the conditions above exist for greater than 5 seconds.
DTC P0134
* DTC P0131, P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274,
P0276, or P0277 is not set.
* The ignition voltage is greater than 10 volts.
* The engine is operating.
* The HO2S 2 is at operating temperature.
* The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
OR
* The HO2S 1 heater duty cycle is greater than 68 percent and the calculated exhaust temperature is greater than 600掳C (1112掳F) for more than
30 seconds.
* The air flow into the engine has exceeded 10 grams.
* DTCs P0134 runs continuously once the conditions above exist for greater than 5 seconds.
Conditions for Setting the DTC
DTC P0131 - Condition 1
The ECM detects that the HO2S 1 signal voltage is less than 60 mV while the corresponding HO2S 2 voltage is greater than 500 mV.
DTC P0131 - Condition 2
The ECM detects that the HO2S 1 signal voltage is less than 60 mV after a cold start with the engine coolant temperature (ECT) less than 40掳C
(104掳F).
DTC P0132
The ECM detects that the HO2S 1 signal voltage is greater than 1,150 mV.
DTC P0134
DTC P0134 sets if any of the following conditions exist:
* An HO2S 1 signal voltage is between 400-600 mV, or 400-550 mV when the calculated exhaust temperature is greater than 800掳C (1,472掳F)
* The calculated internal resistance of a HO2S 1 is greater than 20,000 ohm when the calculated exhaust temperature is greater than 600掳C
