What Does P2231 Mean?
The oxygen sensor signal circuit is shorted to the heater circuit for Bank 1 Sensor 1 (pre-catalytic converter). This creates an abnormal electrical condition where the signal and heater wires are inadvertently connected.
Common Causes
45%
Damaged O2 sensor with internal short between signal and heater elements
30%
Melted or damaged wiring harness causing signal-to-heater short
15%
Damaged connector with crossed or melted terminals
8%
Exhaust heat damage to sensor wiring causing short
2%
PCM internal fault on O2 sensor circuits
Diagnostic Steps
1
Step 1: Visually inspect O2 sensor connector and wiring for melting, damage, or contact between terminals
2
Step 2: Disconnect Bank 1 Sensor 1 O2 sensor and measure resistance between signal and heater circuits (should be open/infinite)
3
Step 3: Check for continuity between signal wire and heater wires at PCM connector with sensor disconnected
4
Step 4: Inspect exhaust manifold area for heat damage to sensor wiring or harness
5
Step 5: Replace O2 sensor if internal short confirmed; repair harness if external short found
Estimated Repair Cost
$150 - $400
Parts + labor, varies by vehicle and location
The oxygen sensor signal circuit is shorted to the heater circuit for Bank 1 Sensor 1 (pre-catalytic converter). This creates an abnormal electrical condition where the signal and heater wires are inadvertently connected.
The most common cause of P2231 (O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1) is: Damaged O2 sensor with internal short between signal and heater elements
Typical repair costs for P2231 range from $150 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Will cause improper fuel control and increased emissions. Safe to drive short distances but may damage catalytic converter if driven extensively.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2231 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions / Fuel Trim
Difficulty
Type
Generic (SAE)
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