P0138 2008 TOYOTA CAMRY Code - Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2
|P0138 2008 TOYOTA CAMRY code possible causes
- Faulty Rear Heated Oxygen Sensor Bank 1
- EFI Relay
- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Intake air leaks
- Exhaust gas leaks
- Inappropriate fuel pressure
- Faulty fuel injectors
|How do I fix the P0138 2008 TOYOTA CAMRY code?Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
|P0138 2008 TOYOTA CAMRY code tech notesReplacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.
There is a factory service bulletin for the following Toyota model:
2008 Toyota Camry
2008 Toyota Camry Service Bulletin OBDII Code P0138
|Cost of diagnosing the P0138 2008 TOYOTA CAMRY code
Labor: 1.0The cost of diagnosing the P0138 2008 TOYOTA CAMRY code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
|When is the P0138 2008 TOYOTA CAMRY code detected?The P0138 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor signal voltage remains excessively high for an extended period of time.
|What are P0138 2008 TOYOTA CAMRY code possible symptoms?
- Engine Light ON (or Service Engine Soon Warning Light)
- High Fuel Consumption
- Excessive Smoke from Exhaust
|P0138 2008 TOYOTA CAMRY code descriptionIn order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel level. For the purpose of helping the ECM to deliver accurate air-fuel ratio control, a Heated Oxygen (HO2) sensor is used.
The HO2 sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low). When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas is rich. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V). Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration in the exhaust gas becomes lean. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is rich (high voltage, i.e. more than 0.45 V). The HO2 sensor has the property of changing its output voltage drastically when the air-fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the HO2 sensor to determine whether the air-fuel ratio after the TWC is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the HO2 sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air-fuel ratio control.
|Need more information with the P0138 2008 TOYOTA CAMRY code?Need more information on how to fix the P0138 2008 TOYOTA CAMRY code?
Get Access to Factory Service Manuals
|Need help with a P0138 2008 TOYOTA CAMRY code?Get the P0138 2008 Toyota Camry code diagnosed by a professional: Find a repair shop in your area
|P0138 2008 TOYOTA CAMRY code commentsHelp us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the P0138 2008 Toyota Camry code? Have you replaced any parts?
Any information is appreciated. Thanks