P0161 Cadillac - HO2S Heater Performance Bank 2 Sensor 2
Repair Importance Level:
Repair Difficulty Level:
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks
- Exhaust gas leaks
Replacing the Rear Heated Oxygen Sensor Bank 2 usually takes care of the problem
When is the code detected?
The Powertrain Control Module (PCM) runs the heater test only on a cold start (depends on the cumulative air flow) and only once an ignition cycle. When you start the engine the PCM monitors the HO2S voltage. When the HO2S voltage goes above or below the bias range threshold, the PCM determines how much time it took. If the PCM detects that the process took too much time for the HO2S to enter into normal operating range, the P0161 code will set. The time the process takes the HO2S to reach operating temperature is based on the amount of air that flows into the engine.
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible higher than usual fuel consumption
P0161 Cadillac Description
The Powertrain Control Module (PCM) supplies a bias voltage (approximately 450 mV) on the Heated Oxygen Sensor (HO2S) signal high and low circuits. When you turn the ignition to the ON position, battery voltage is supplied to the HO2S heater. As the heater reaches the operating temperature, the HO2S voltage responds by changing from a bias voltage range to the normal operation. Typically, as the HO2S reaches the operating temperature, the HO2S voltage goes from a bias voltage to a voltage below 300 mV. Depending on the exhaust gas content, it is possible for the HO2S voltage to go above 450 mV.
Need more help?
Do you need more help with the P0161 Cadillac code? ask a question to our users or search the top hand picked automotive forums for more information
CADILLAC Technical Service Bulletins for P0161 code
2004 CADILLAC CTS Electrical System Details
Repair Shops Around Your Area
Need parts to fix this code? Search hundreds of stores at the same time and compare prices
Help us improve Engine-Codes.com. Leave a comment below or tell us if the information above help you fix the code. What are symptoms is your vehicle for the P0161 Cadillac code? Have you replaced any parts?
Any information is appreciated. Thanks