Code
P0167
GWM
P — Powertrain
- O2 sensor heating circuit fault (bank 2, sensor 3)
AI status
Completed
Completed
100%
Causes
- Blown fuse or failed relay supplying heater circuit
- Open or shorted wiring/connector to Bank 2 Sensor 3 heater
- Corroded/loose connector or poor ground
- Failed O2 sensor (heater element open or shorted)
- PCM / heater control driver fault
- Aftermarket or incorrect sensor with wrong heater resistance
Symptoms
- Check Engine Light (MIL) illuminated
- Possible failed emissions test (increased tailpipe emissions)
- Heater-related readiness monitors may not set
- Possible reduced closed-loop efficiency or fuel trim impact under cold operation (minor)
What to check
- Scan tool: confirm P0167, note freeze frame and readiness status
- Check for other O2/catalyst related codes (stores useful context)
- Visually inspect sensor, connector, and wiring (heat, chafing, corrosion)
- Check relevant fuse(s) and relay for heater circuit
- Backprobe heater power/ground during key ON/engine cranking and with engine running
- Measure heater resistance across sensor heater pins (compare to spec)
Signal parameters
- Heater supply voltage: ~Battery voltage (key ON/engine running) when heater commanded ON
- Heater control: PCM typically switches ground (or power) to activate heater
- Heater resistance: varies by sensor — typically low ohms (example ranges ~2–20 Ω); use manufacturer spec
- Diagnostic threshold: PCM monitors current/voltage; code set when heater circuit is open, shorted to ground, shorted to voltage, or draws excessive/insufficient current
Diagnostic algorithm
- Connect a scan tool, record freeze frame and pending codes. Confirm P0167 is current and note heater control status/readings.
- Visually inspect Bank 2 Sensor 3 and harness for heat damage, cuts, pin corrosion, or connector contamination. Repair obvious damage.
- With ignition OFF, unplug sensor. Inspect pins for corrosion and continuity to PCM connector. Check for bent/missing pins.
- Measure heater element resistance across the sensor heater terminals. Compare to GWM specification. Very high/OL indicates open heater (replace sensor). Very low indicates short.
- With key ON (engine off) backprobe the heater power terminal — verify battery voltage or fused supply is present. If no supply, check fuse/relay and wiring to supply source.
- Command heater ON with scan tool (if supported) and monitor voltage/current at heater terminals. Confirm PCM is commanding and that circuit responds. If PCM grounds to switch, verify ground is present when commanded.
- If supply and command are present but heater element resistance is correct and no heater operation, suspect PCM driver fault — confirm by swapping with a known good identical sensor (or temporarily using bench supply) before replacing PCM.
- Repair or replace failed component (sensor, wiring, connector, fuse/relay, or PCM) and clear codes. Verify proper operation and that readiness monitors complete.
Likely causes
- Damaged wire insulation or chafed harness near exhaust
- Connector contaminated with corrosion or moisture
- Internal heater element failure in the sensor (most common)
- Blown inline fuse or tripped relay for heater supply
- PCM transistor or driver has failed (less common)
Fault status
Status
MIL ON — PCM detected improper heater circuit operation for O2 sensor Bank 2 Sensor 3. Heater supply, ground, or heater element is out of expected range causing P0167 to set.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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