Contents Wiring diagrams Section: Testing & Diagnostics All sections

Dtcs P000A to P0140: Overview Dodge Durango III

Testing & Diagnostics 2 illustrations ~4622 words

Scheme 14

Scheme 14: P000A-BANK 1 CAMSHAFT 1 POSITION SLOW RESPONSE (3.6L)

Scheme 15

Scheme 15

Note. The CMP sensor is a dual read sensor reading both camshafts of it's correlating bank.

3.6L VVT Component Locations
CALLOUTDESCRIPTION
1VVT Actuator Bank 1 Position 2
2VVT Actuator Bank 1 Position 1
3VVT Actuator Bank 2 Position 1
4VVT Actuator Bank 2 Position 2
5Camshaft Bank 2 Position 1
6Bank 2 Camshaft Sensor
7Camshaft Bank 2 Position 2
8Camshaft Bank 1 Position 2
9Bank 1 Camshaft Sensor
10Camshaft Bank 1 Position 1

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

THEORY OF OPERATION

Variable Valve Timing (VVT) allows the PCM to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

Variable Valve Timing (VVT) allows the PCM to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

Variable Cam Timing (VCT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of the camshaft, based on desired torque levels and engine operating conditions. The camshaft design allows for the exhaust lobes to be adjusted while the intake lobes are not adjustable all on one camshaft. The PCM controls a solenoid operated control valve, that is used to direct oil pressure to hydraulic actuator mounted between the camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of the camshaft relative to crankshaft rotation. A sensor is used to monitor the position of the camshaft.

Variable Valve Timing (VVT) allows the PCM to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

Variable Valve Timing (VVT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

Variable Valve Timing (VVT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

Variable Valve Timing (VVT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

Variable Cam Timing (VCT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of the camshaft, based on desired torque levels and engine operating conditions. The camshaft design allows for the exhaust lobes to be adjusted while the intake lobes are not adjustable all on one camshaft. The PCM controls a solenoid operated control valve, that is used to direct oil pressure to hydraulic actuator mounted between the camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of the camshaft relative to crankshaft rotation. A sensor is used to monitor the position of the camshaft.

Variable Cam Timing (VCT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of the camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves that are used to direct oil pressure to hydraulic actuators mounted between the camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of the camshaft relative to crankshaft rotation. A sensor is used to monitor the position of the camshaft.

Variable Valve Timing (VVT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of each camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves, one for each camshaft, that are used to direct oil pressure to hydraulic actuators mounted between each camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each camshaft relative to crankshaft rotation. A sensor is used to monitor the position of each camshaft.

The 3.6L has four separate camshafts that the Powertrain Control Module (PCM) requires positional information from. There are two Camshaft Position (CMP) sensors on the 3.6L, each CMP sensor consists of four circuits. The sensors are located on the top end of each valve cover, closest to the transmission side of the engine. The CMP sensor is an integrated circuit sensing device and on the end of each camshaft is a magnetic encoder that is programmed with a magnetic pattern. The PCM provides a 5-volt supply and a sensor ground circuit to the CMP sensor and the CMP Sensor provides two camshaft positional signals, the intake and exhaust camshaft position, to the PCM. The sensor detects the magnetically encoded information, a series of magnetic peaks and valleys, from the encoder. As each camshaft rotates, the magnetic encoded pattern passes by the CMP sensor creating a changing magnetic field at the sensor face. The changing magnetic field is interpreted by the sensor electronics and a digital output, ON/OFF or HIGH/LOW pattern, is produced. The length of the pulse widths generated by the CMP varies in size based on the velocity of the camshaft. The PCM decodes the digital pattern to identify the camshaft position. The information from each individual camshaft along with the crankshaft information is used to control and sequence the Variable Valve Timing (VVT) system and fuel injection events.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

Ambient Air Temperature (AAT) sensor performance looks at the outputs of three temperature sensors and compares them under cold start conditions. The AAT reading is a bussed message from the Totally Integrated Power Module (TIPM) to the Powertrain Control Module (PCM). The AAT sensor is a variable resistor that measures the ambient air temperature. The TIPM supplies a 5 volt reference and a ground to the sensors low reference signal circuit. When the AAT is low, the sensor resistance is high. When the AAT is high, the sensor resistance is low. Following a start to run delay time, the outputs of the ambient, engine coolant and intake air temperature sensors are compared. If the engine coolant and intake air temperature sensors agree and the ambient air temperature does not agree, the ambient air temperature sensor is declared as irrational. If declared irrational a second comparison will be done after a short drive cycle.

Ambient Air Temperature (AAT) sensor performance looks at the outputs of three temperature sensors and compares them under cold start conditions. The AAT reading is a bussed message from the Totally Integrated Power Module (TIPM) to the Powertrain Control Module (PCM). Following a start to run delay time, the outputs of the ambient, engine coolant and intake air temperature sensors are compared. The AAT sensor is a variable resistor that measures the ambient air temperature. The TIPM supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the AAT is low, the sensor resistance is high. When the AAT is high, the sensor resistance is low.

Ambient Air Temperature (AAT) sensor performance looks at the outputs of three temperature sensors and compares them under cold start conditions. The AAT reading is a bussed message from the Totally Integrated Power Module (TIPM) to the Powertrain Control Module (PCM). Following a start to run delay time, the outputs of the ambient, engine coolant and intake air temperature sensors are compared. The AAT sensor is a variable resistor that measures the ambient air temperature. The TIPM supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the AAT is low, the sensor resistance is high. When the AAT is high, the sensor resistance is low.

The Manifold Absolute Pressure (MAP) sensor is a transducer that varies resistance according to changes in altitude and atmospheric conditions. The MAP reading gives the Powertrain Control Module (PCM) an indication of the current air pressure within the intake manifold. The PCM uses this information to calculate fuel delivery. The MAP sensor has a 5 Volt reference circuit, a low reference circuit and a signal circuit. The PCM supplies 5 Volts to the MAP sensor on a 5 Volt reference circuit and provides a ground on a low reference circuit. The MAP sensor provides a voltage signal to the PCM on a signal circuit relative to the pressure changes.

The Manifold Absolute Pressure (MAP) sensor is a transducer that varies resistance according to changes in altitude and atmospheric conditions. The MAP reading gives the Powertrain Control Module (PCM) an indication of the current air pressure within the intake manifold. The PCM uses this information to calculate fuel delivery. The MAP sensor has a 5 Volt reference circuit, a low reference circuit and a signal circuit. The PCM supplies 5 Volts to the MAP sensor on a 5 Volt reference circuit and provides a ground on a low reference circuit. The MAP sensor provides a voltage signal to the PCM on a signal circuit relative to the pressure changes.

Intake Air Temperature Sensor performance looks at the outputs of three temperature sensors and compares them under cold start conditions. Following a start to run delay time, the outputs of the ambient, engine coolant and intake air temperature sensors will be compared. If the engine coolant and ambient air temperature sensors agree and the intake air temperature does not agree, the intake air temperature sensor is declared as irrational. If declared irrational a second comparison will be done after a short drive cycle.

Engine Coolant Temperature Sensor performance looks at the outputs of three temperature sensors and compares them under cold start conditions. Following a start to run delay time, the outputs of the ambient, engine coolant and intake air temperature sensors will be compared. If the intake air and ambient air temperature sensors agree and the engine coolant temperature does not agree, the engine coolant temperature sensor is declared as irrational.

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The TPS sensors 1 and 2 are located within the throttle body assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The TPS sensors 1 and 2 are located within the throttle body assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The TPS sensors 1 and 2 are located within the throttle body assembly. Each sensor has a 5 Volt reference circuit, a low reference circuit and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

The Engine Coolant Temperature (ECT) sensor is a negative temperature coefficient thermistor-type sensor whose resistance varies inversely with temperature. At cold temperatures the sensor resistance is high so the voltage is high. As the coolant temperature increases the resistance decreases and the voltage becomes low. The INSUFFICIENT COOLANT TEMP FOR CLOSED-LOOP FUEL CONTROL determines if the engine coolant temperature will reach the closed loop fueling control temperature limit in a regulated time after start.

The Powertrain Control Module (PCM) predicts what the engine coolant temperature should be, based on the engine coolant temperature at start-up, ambient temperature and how the vehicle is subsequently driven. The predicted engine coolant temperature is compared to the Engine Coolant Temperature Sensor reading. The error between the two is calculated and integrated with respect to time. When the Thermostat diagnostic runs, the integrated error is compared to a calibrated threshold and pass/fail is determined. Separate pass and fail thresholds are used in order to improve accuracy of the diagnostic.

The barometric pressure (BARO) sensor is the Manifold Absolute Pressure (MAP) sensor which is a transducer that varies resistance according to changes in altitude and atmospheric conditions. The BARO reading, which is read the first few moments before engine cranking, gives the Powertrain Control Module (PCM) an indication of the current barometric pressure. The PCM uses this information to calculate fuel delivery. The MAP sensor has a 5 Volt reference circuit, a low reference circuit and a signal circuit. The PCM supplies 5 Volts to the MAP sensor on a 5 Volt reference circuit and provides a ground on a low reference circuit. The MAP sensor provides a voltage signal to the PCM on a signal circuit relative to the pressure changes. The PCM monitors the stability of the BARO reading output by comparing successive samples.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

For an aged O2 sensor, the response rate to the air/fuel change is slower than when it was new. The O2 sensor tends to move less with the same air/fuel changes in a given time frame. Therefore by observing the activity of voltage readings from the upstream O2 sensor, the quality of the O2 sensor can be detected.

This diagnostic provides a continuous check of the O2 heater circuit during operation. The heater circuit is momentarily disabled to allow a resistance measurement to be taken to calculate heater temperature. The current delivery to the heater is duty cycled to maintain a specific target temperature. The error from the target temperature is continuously monitored to determine heater performance.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

The downstream O2 Sensor is located in the exhaust path behind the catalytic converter, is monitored for proper response to assure optimum catalytic converter efficiency. The downstream O2 response monitor is intended to diagnose a downstream O2 sensor that is not moving or stuck in a voltage window and to insure accurate information for catalyst monitor diagnosis.

The downstream O2 Sensor is located in the exhaust path behind the catalytic converter, is monitored for proper response to assure optimum catalytic converter efficiency. The downstream O2 response monitor is intended to diagnose a downstream O2 sensor that is not moving or stuck in a voltage window and to insure accurate information for catalyst monitor diagnosis.

See also:
STANDARD PROCEDURE