Hint:
Description
Refer to dtc p2195 (see page es-292).
Hint:
Monitor description
The ecm uses information from the air-fuel ratio (a/f) sensor to regulate the air-fuel ratio and keep it close to the stoichiometric level. This maximizes the ability of the three-way catalytic converter (twc) to purify the exhaust gases.
The a/f sensor detects oxygen levels in the exhaust gas and transmits the information to the ecm. The inner surface of the sensor element is exposed to the outside air. The outer surface of the sensor element is exposed to the exhaust gas. The sensor element is made of platinum coated zirconia and includes an integrated heating element.
The zirconia element generates a small voltage when there is a large difference in the oxygen concentrations between the exhaust gas and outside air. The platinum coating amplifies this voltage generation.
The a/f sensor is more efficient when heated. When the exhaust gas temperature is low, the sensor cannot generate useful voltage signals without supplementary heating. The ecm regulates the supplementary heating using a duty-cycle approach to adjust the average current in the sensor heater element. If the heater current is outside the normal range, the signal transmitted by the a/f sensor becomes inaccurate, as a result, the ecm is unable to regulate air-fuel ratio properly.
When the current in the a/f sensor heater is outside the normal operating range, the ecm interprets this as a malfunction in the sensor heater and sets a dtc.
Example: the ecm sets dtc p0032 when the current in the a/f sensor heater is more than 10 a. Conversely, when the heater current is less than 0.8 A, dtc p0031 is set.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Component operating range
Wiring diagram
Refer to dtc p2195 (see page es-296).
Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
Standard resistance
Standard voltage
Standard resistance: below 1
Standard resistance
Standard resistance (check for open)
Standard resistance (check for short)
Standard resistance (check for open)
Standard resistance (check for short)
Oxygen sensor heater control circuit
Description
Refer to dtc p0136 (see page es-129).
Hint:
Monitor description
The sensing position of the heated oxygen (ho2) sensor has a zirconia element which is used to detect the oxygen concentration in the exhaust gas. If the zirconia element is at the appropriate temperature, and the difference between the oxygen concentrations surrounding the inside and outside surfaces of the sensor is large, the zirconia element generates voltage signals. In order to increase the oxygen concentration detecting capacity of the zirconia element, the ecm supplements the heat from the exhaust with heat from a heating element inside the sensor.
Heated oxygen sensor heater range check (p0037 and p0038): the ecm monitors the current applied to the o2 sensor heater to check the heater for malfunctions. If the current is below the threshold value, the ecm determines that there is an open circuit in the heater. If the current is above the threshold value, the ecm determines that there is a short circuit in the heater.
The ecm constantly monitors the current applied to the heater. If the ecm detects an open or short circuit, the ecm turns the mil on and sets a dtc.
If a malfunction is detected, the ecm cuts off the current applied to the heater.
Example: the ecm sets dtc p0038 when the current in the ho2 sensor heater is more than 2 a. Conversely, when the heater current is less than 0.3 A, dtc p0037 is set.
Heated oxygen sensor heater performance (p0141): after the accumulated heater on time exceeds 100 seconds, the ecm calculates the heater resistance using the battery voltage and the current applied to the heater.
If the resistance is above the threshold value, the ecm determines that there is a malfunction in the ho2 sensor heater and set dtc p0141.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Component operating range
Wiring diagram
Refer to dtc p0136 (see page es-136).
Confirmation driving pattern
These dtcs are detected when the engine idles for 110 seconds or more.
Inspection procedure
Hint:
Sensor 2 refers to the sensor mounted behind the three-way catalytic converter (twc) and located far from the engine assembly.
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
Standard resistance
Standard voltage
Standard resistance (check for open)
Standard resistance (check for short)
Standard resistance (check for open)
Standard resistance (check for short)
Engine (ignition) switch
(vehicles with a
smart key system)
Performing the following operations when carrying the electronic
key on your person starts the engine or changes engine
switch modes.
Starting the engine
Check that the parking brake is set.
Check that the shift lever is set in p.
Firmly depress the brake pedal.
The smart key system in ...
General maintenance (2006/01- )
Inspect steering linkage and gear housing
Check the steering wheel free play.
Check the steering linkage for looseness or
damage.
Check that the tie rod ends do not have
excessive play.
Check that the dust seals and boots are not
damaged.
Check that the boot clamps are not ...
Front axle hub
Components (2005/11-2006/01)
Components (2006/01- )
On-vehicle inspection
Check front axle hub bearing
Remove the front wheel.
Disconnect the front disc brake cylinder (see page
br-40).
Remove the front disc.
Inspect the axle hub backlash.
Using a dial indicator ...