What Does P1136 Mean?
This code indicates the O2 sensor heater circuit for Bank 1, Sensor 1 is producing a higher voltage than expected. The ECM detected excessive voltage in the heater control circuit, which may indicate a short to power, a stuck relay, or an internal sensor fault. High voltage in the heater circuit can damage the sensor element and cause inaccurate fuel metering readings.
Common Causes
30%
Short to battery voltage in the O2 sensor heater wiring harness
25%
Heater relay stuck closed providing continuous power to the circuit
20%
Internally shorted O2 sensor heater element
15%
ECM heater driver circuit failure (internal short)
10%
Incorrect O2 sensor installed with wrong heater resistance
Diagnostic Steps
1
Disconnect the Bank 1 Sensor 1 O2 sensor connector and measure heater circuit voltage from the harness side with key on; compare to expected ECM-controlled voltage.
2
Check for shorts in the heater wiring by measuring resistance between the heater circuit wires and battery positive.
3
Measure the O2 sensor heater resistance and compare to manufacturer specification.
4
Inspect the heater relay (if applicable) for proper operation; check for welded contacts.
5
Verify the correct O2 sensor part number is installed for the vehicle application.
6
If wiring and sensor check good, suspect ECM heater driver fault.
Estimated Repair Cost
$100 - $400
Parts + labor, varies by vehicle and location
This code indicates the O2 sensor heater circuit for Bank 1, Sensor 1 is producing a higher voltage than expected. The ECM detected excessive voltage in the heater control circuit, which may indicate a short to power, a stuck relay, or an internal sensor fault. High voltage in the heater circuit can...
The most common cause of P1136 (O2 Sensor Heater Circuit High Voltage (Bank 1 Sensor 1)) is: Short to battery voltage in the O2 sensor heater wiring harness
Typical repair costs for P1136 range from $100 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A short-to-power condition in the heater circuit poses a minor risk of wiring overheating. While unlikely to cause a fire, it can damage the O2 sensor and ECM driver circuit if left unaddressed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1136 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System / Emissions
Difficulty
Type
Manufacturer
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