The impedance cannot be measured using an ohmmeter.
DTCs P0136 and P0156 indicate the deterioration of the HO2 sensor. The ECM sets the DTCs by
calculating the impedance of the sensor when the typical enabling conditions are satisfied (2
driving cycles).
DTCs P0137 and P0157 indicate an open or short circuit in the HO2 sensor (2 driving cycles). The
ECM sets the DTCs when the impedance of the sensor exceeds the threshold 15 kohms.
Fig. 82: High Or Low Impedance Of Heated Oxygen (HO2) Sensor
5. HO2 sensor output voltage fuel cut (P0139 or P0159)
The sensor voltage drops below 0.2 V (extremely lean status) immediately when the vehicle decelerates
and fuel cut is operating. If the voltage does not drop below 0.2 V, the ECM determines that the sensor
response feature has deteriorated, illuminates the MIL and stores DTC (s).
MONITOR STRATEGY
MONITOR STRATEGY
Related DTCs
P0136: Heated oxygen sensor output voltage (Output voltage) (bank 1)
P0136: Heated oxygen sensor impedance (Low) (bank 1)
P0137: Heated oxygen sensor output voltage (Low voltage) (bank 1)
P0137: Heated oxygen sensor impedance (High) (bank 1)
P0138: Heated oxygen sensor output voltage (High voltage) (bank 1)
P0138: Heated oxygen sensor output voltage (Extremely high) (bank 1)
P0139: Heated oxygen sensor output voltage during fuel cut (bank 1)
P0156: Heated oxygen sensor output voltage (Output voltage) (bank 2)
P0156: Heated oxygen sensor impedance (Low) (bank 2)
P0157: Heated oxygen sensor output voltage (Low voltage) (bank 2)
P0157: Heated oxygen sensor impedance (High) (bank 2)
P0158: Heated oxygen sensor output voltage (High voltage) (bank 2)
P0158: Heated oxygen sensor impedance (Extremely high) (bank 2)
P0159: Heated oxygen sensor output voltage during fuel cut (bank 2)
2008 Toyota Tundra
2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra