Code
P1167
INFINITI
P — Powertrain
HO2S11 Heater Circuit VS+ Fault Bank 1 Sensor 1
AI status
Completed
Completed
100%
Causes
- Open or short in the HO2S11 heater supply (VS+) circuit
- Corroded or loose sensor connector/pins
- Blown fuse or faulty relay supplying heater power
- Failed oxygen sensor (heater element open or shorted)
- PCM/ECM driver fault or internal short
- Poor battery voltage or ground issues
Symptoms
- Check Engine Light (MIL) illuminated
- Reduced fuel economy and increased emissions
- Failure to set O2 sensor heater readiness (EVAP/catalyst readiness may fail)
- Possible rough idle or reduced driveability (if oxygen sensor not reaching operating temp)
- Failed emissions test
What to check
- Read and record all stored codes and freeze frame data
- Check live data: O2 sensor heater status and sensor voltage if available
- Verify battery voltage and ground integrity
- Visual inspection of sensor connector, wiring harness, and chassis grounds
- Check related fuses and relays for the heater circuit
- Measure heater resistance at the sensor (with connector disconnected)
Signal parameters
- Heater supply voltage (VS+): approximately battery voltage when heater is powered — ~11–14 V
- Heater resistance (typical range): roughly 5–20 ohms (vehicle-specific; consult service data)
- Heater current: typically on the order of 0.5–3 A when energized (varies by sensor)
- O2 sensor output voltage (sensor operation): 0–1.0 V (not the heater circuit but useful for related checks)
Diagnostic algorithm
- Confirm code presence and note freeze frame/driving conditions. Check for related codes (other O2 heater or sensor codes).
- Visually inspect Bank 1 Sensor 1 connector and wiring for damage, corrosion, pin push-out or water intrusion. Repair as needed.
- Check relevant fuses and relays for the O2 heater circuit; replace if blown and investigate cause.
- With ignition OFF, disconnect the sensor and measure heater element resistance across heater terminals. Compare to spec; open or extremely high resistance indicates failed heater.
- Check continuity between sensor heater terminals and the harness/PCM connector. Look for shorts to battery (VB) or to ground.
- With key ON (engine off) and using a scan tool, command the heater ON if possible. Backprobe the harness at the sensor connector: verify VS+ supply voltage and PCM switch/ground signal depending on circuit design.
- Wiggle harness and connector while monitoring to reproduce fault. Repair any intermittent faults found.
- If wiring, connector, and fuses are good but heater resistance is out of spec or no heater supply present at the connector, replace the sensor and retest.
- If fault persists after sensor replacement and wiring checks, test/replace PCM only after confirming all harness and power/ground circuits are correct and documented.
Likely causes
- Damaged/shorted wiring between sensor and fuse/ignition supply
- Connector corrosion or poor terminal contact at sensor
- Failed heater element in the Bank 1 Sensor 1 O2 sensor
- Blown heater fuse or bad relay for sensor heater supply
- Faulty PCM heater supply driver (less common)
Fault status
Status
HO2S11 Heater Circuit VS+ Fault (Bank 1 Sensor 1). The power/supply side of the heater circuit for upstream oxygen sensor Bank 1 Sensor 1 is malfunctioning. Inspect sensor, fuse/relay, wiring, connectors and PCM heater driver.
Repair difficulty: Medium
Diagnostic time: 0.5-2 hours
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