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Home / DTC / P0144 — O2 Sensor Circuit High Voltage Bank 1 Sensor 3

P0144 — O2 Sensor Circuit High Voltage Bank 1 Sensor 3

Detailed page for trouble code P0144.

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Code

P0144

Generic P — Powertrain

O2 Sensor Circuit High Voltage Bank 1 Sensor 3

Brand: Generic
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty Bank 1 Sensor 3 (downstream O2 sensor)
  • Voltage short to battery/ignition feed on sensor signal wire
  • Contaminated or damaged sensor (silicone, oil, fuel, coolant)
  • Excessive fuel (rich running) or exhaust leak upstream affecting readings
  • Poor ground or connector corrosion
  • Heater circuit fault causing abnormal sensor behavior

Symptoms

  • Check Engine Light (MIL) illuminated
  • Possible failed emissions test (high emissions)
  • Reduced fuel economy if the ECM is compensating
  • Usually no pronounced driveability symptoms, but long-term rich condition may cause fouled plugs or catalytic damage

What to check

  • Pull stored freeze frame and live data with a scan tool and confirm P0144 is current
  • Visually inspect sensor connector and wiring for damage, corrosion, melted insulation, or pin pushed out
  • Backprobe sensor signal with a digital multimeter or lab scope and compare to expected voltage
  • Check for short to battery: measure signal wire voltage with ignition on (should not be constant near battery voltage)
  • Check sensor heater circuit for proper resistance and power/ground
  • Scan fuel trims (short and long term) for signs of rich condition

Signal parameters

  • Expected downstream (post-cat) O2 sensor voltage: often relatively steady near ~0.4–0.6 V when closed-loop and cat working; should not be constantly >0.8 V
  • Upstream (pre-cat) O2 sensors normally oscillate ~0.1–0.9 V rapidly
  • High-voltage threshold that may set P0144: sustained sensor signal near or above ~0.8–1.0 V (varies by manufacturer)
  • Typical heater circuit resistance (sensor dependent): roughly 2–20 ohms; check manufacturer spec

Diagnostic algorithm

  1. Read and record freeze frame and pending codes; clear code and retest to confirm repeatability.
  2. Visual inspection: check sensor body, connector, wiring harness and ground points for damage, corrosion, or exposure to heat/oil/coolant.
  3. Backprobe the signal wire with the engine running: observe voltage with a scan tool or meter. If voltage is constantly high (~>0.8 V), suspect short to power or sensor stuck high.
  4. With ignition on (engine off) measure signal wire voltage; if ~12 V or near battery voltage, wiring is shorted to power — locate and repair short.
  5. Test heater circuit: with connector disconnected measure resistance between heater pins and check for battery voltage to heater circuit with ignition on; repair as needed.
  6. Wiggle test harness while monitoring signal to find intermittent opens/shorts.
  7. Compare upstream and downstream sensor behavior. If downstream mirrors upstream continuously high, check upstream issues (rich condition, injector problem, fuel pressure).
  8. Inspect for exhaust leaks or clogged/failed catalytic converter (backpressure test) if sensor readings are abnormal despite good wiring.
  9. If wiring and vehicle systems test good, replace the downstream O2 sensor; clear codes and road test to verify resolution.
  10. If problem persists after sensor replacement, suspect PCM fault and perform PCM-specific checks or consult manufacturer service information.

Likely causes

  • Damaged or shorted signal wiring to battery/ignition feed
  • Failed downstream O2 sensor (Bank 1 Sensor 3)
  • Connector corrosion or poor ground at sensor
  • Exhaust contamination or restrictive catalytic converter causing abnormal reading
  • Less likely: PCM internal fault

Fault status

⚠️ Status
ECM detected a persistently high voltage from the Bank 1 Sensor 3 oxygen sensor circuit, indicating the sensor signal is higher than expected or the circuit is shorted to a power source.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours
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Code

P0144

GWM P — Powertrain

- High oxygen sensor circuit voltage (bank 1, sensor 3)

Brand: GWM
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty Bank 1 Sensor 3 (downstream O2 sensor)
  • Voltage short to battery/ignition feed on sensor signal wire
  • Contaminated or damaged sensor (silicone, oil, fuel, coolant)
  • Excessive fuel (rich running) or exhaust leak upstream affecting readings
  • Poor ground or connector corrosion
  • Heater circuit fault causing abnormal sensor behavior

Symptoms

  • Check Engine Light (MIL) illuminated
  • Possible failed emissions test (high emissions)
  • Reduced fuel economy if the ECM is compensating
  • Usually no pronounced driveability symptoms, but long-term rich condition may cause fouled plugs or catalytic damage

What to check

  • Pull stored freeze frame and live data with a scan tool and confirm P0144 is current
  • Visually inspect sensor connector and wiring for damage, corrosion, melted insulation, or pin pushed out
  • Backprobe sensor signal with a digital multimeter or lab scope and compare to expected voltage
  • Check for short to battery: measure signal wire voltage with ignition on (should not be constant near battery voltage)
  • Check sensor heater circuit for proper resistance and power/ground
  • Scan fuel trims (short and long term) for signs of rich condition

Signal parameters

  • Expected downstream (post-cat) O2 sensor voltage: often relatively steady near ~0.4–0.6 V when closed-loop and cat working; should not be constantly >0.8 V
  • Upstream (pre-cat) O2 sensors normally oscillate ~0.1–0.9 V rapidly
  • High-voltage threshold that may set P0144: sustained sensor signal near or above ~0.8–1.0 V (varies by manufacturer)
  • Typical heater circuit resistance (sensor dependent): roughly 2–20 ohms; check manufacturer spec

Diagnostic algorithm

  1. Read and record freeze frame and pending codes; clear code and retest to confirm repeatability.
  2. Visual inspection: check sensor body, connector, wiring harness and ground points for damage, corrosion, or exposure to heat/oil/coolant.
  3. Backprobe the signal wire with the engine running: observe voltage with a scan tool or meter. If voltage is constantly high (~>0.8 V), suspect short to power or sensor stuck high.
  4. With ignition on (engine off) measure signal wire voltage; if ~12 V or near battery voltage, wiring is shorted to power — locate and repair short.
  5. Test heater circuit: with connector disconnected measure resistance between heater pins and check for battery voltage to heater circuit with ignition on; repair as needed.
  6. Wiggle test harness while monitoring signal to find intermittent opens/shorts.
  7. Compare upstream and downstream sensor behavior. If downstream mirrors upstream continuously high, check upstream issues (rich condition, injector problem, fuel pressure).
  8. Inspect for exhaust leaks or clogged/failed catalytic converter (backpressure test) if sensor readings are abnormal despite good wiring.
  9. If wiring and vehicle systems test good, replace the downstream O2 sensor; clear codes and road test to verify resolution.
  10. If problem persists after sensor replacement, suspect PCM fault and perform PCM-specific checks or consult manufacturer service information.

Likely causes

  • Damaged or shorted signal wiring to battery/ignition feed
  • Failed downstream O2 sensor (Bank 1 Sensor 3)
  • Connector corrosion or poor ground at sensor
  • Exhaust contamination or restrictive catalytic converter causing abnormal reading
  • Less likely: PCM internal fault

Fault status

⚠️ Status
ECM detected a persistently high voltage from the Bank 1 Sensor 3 oxygen sensor circuit, indicating the sensor signal is higher than expected or the circuit is shorted to a power source.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours
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Code

P0144

HUMMER P — Powertrain

Heated Oxygen Sensor (HO2S) Circuit High Voltage Bank 1 Sensor 3

Brand: HUMMER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty Bank 1 Sensor 3 (downstream O2 sensor)
  • Voltage short to battery/ignition feed on sensor signal wire
  • Contaminated or damaged sensor (silicone, oil, fuel, coolant)
  • Excessive fuel (rich running) or exhaust leak upstream affecting readings
  • Poor ground or connector corrosion
  • Heater circuit fault causing abnormal sensor behavior

Symptoms

  • Check Engine Light (MIL) illuminated
  • Possible failed emissions test (high emissions)
  • Reduced fuel economy if the ECM is compensating
  • Usually no pronounced driveability symptoms, but long-term rich condition may cause fouled plugs or catalytic damage

What to check

  • Pull stored freeze frame and live data with a scan tool and confirm P0144 is current
  • Visually inspect sensor connector and wiring for damage, corrosion, melted insulation, or pin pushed out
  • Backprobe sensor signal with a digital multimeter or lab scope and compare to expected voltage
  • Check for short to battery: measure signal wire voltage with ignition on (should not be constant near battery voltage)
  • Check sensor heater circuit for proper resistance and power/ground
  • Scan fuel trims (short and long term) for signs of rich condition

Signal parameters

  • Expected downstream (post-cat) O2 sensor voltage: often relatively steady near ~0.4–0.6 V when closed-loop and cat working; should not be constantly >0.8 V
  • Upstream (pre-cat) O2 sensors normally oscillate ~0.1–0.9 V rapidly
  • High-voltage threshold that may set P0144: sustained sensor signal near or above ~0.8–1.0 V (varies by manufacturer)
  • Typical heater circuit resistance (sensor dependent): roughly 2–20 ohms; check manufacturer spec

Diagnostic algorithm

  1. Read and record freeze frame and pending codes; clear code and retest to confirm repeatability.
  2. Visual inspection: check sensor body, connector, wiring harness and ground points for damage, corrosion, or exposure to heat/oil/coolant.
  3. Backprobe the signal wire with the engine running: observe voltage with a scan tool or meter. If voltage is constantly high (~>0.8 V), suspect short to power or sensor stuck high.
  4. With ignition on (engine off) measure signal wire voltage; if ~12 V or near battery voltage, wiring is shorted to power — locate and repair short.
  5. Test heater circuit: with connector disconnected measure resistance between heater pins and check for battery voltage to heater circuit with ignition on; repair as needed.
  6. Wiggle test harness while monitoring signal to find intermittent opens/shorts.
  7. Compare upstream and downstream sensor behavior. If downstream mirrors upstream continuously high, check upstream issues (rich condition, injector problem, fuel pressure).
  8. Inspect for exhaust leaks or clogged/failed catalytic converter (backpressure test) if sensor readings are abnormal despite good wiring.
  9. If wiring and vehicle systems test good, replace the downstream O2 sensor; clear codes and road test to verify resolution.
  10. If problem persists after sensor replacement, suspect PCM fault and perform PCM-specific checks or consult manufacturer service information.

Likely causes

  • Damaged or shorted signal wiring to battery/ignition feed
  • Failed downstream O2 sensor (Bank 1 Sensor 3)
  • Connector corrosion or poor ground at sensor
  • Exhaust contamination or restrictive catalytic converter causing abnormal reading
  • Less likely: PCM internal fault

Fault status

⚠️ Status
ECM detected a persistently high voltage from the Bank 1 Sensor 3 oxygen sensor circuit, indicating the sensor signal is higher than expected or the circuit is shorted to a power source.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours
Repair manuals

Manual library for HUMMER

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Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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Code

P0144

LAND ROVER P — Powertrain

Oxygen sensor - high voltage circuit. Bank 1 - sensor 3

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty Bank 1 Sensor 3 (downstream O2 sensor)
  • Voltage short to battery/ignition feed on sensor signal wire
  • Contaminated or damaged sensor (silicone, oil, fuel, coolant)
  • Excessive fuel (rich running) or exhaust leak upstream affecting readings
  • Poor ground or connector corrosion
  • Heater circuit fault causing abnormal sensor behavior

Symptoms

  • Check Engine Light (MIL) illuminated
  • Possible failed emissions test (high emissions)
  • Reduced fuel economy if the ECM is compensating
  • Usually no pronounced driveability symptoms, but long-term rich condition may cause fouled plugs or catalytic damage

What to check

  • Pull stored freeze frame and live data with a scan tool and confirm P0144 is current
  • Visually inspect sensor connector and wiring for damage, corrosion, melted insulation, or pin pushed out
  • Backprobe sensor signal with a digital multimeter or lab scope and compare to expected voltage
  • Check for short to battery: measure signal wire voltage with ignition on (should not be constant near battery voltage)
  • Check sensor heater circuit for proper resistance and power/ground
  • Scan fuel trims (short and long term) for signs of rich condition

Signal parameters

  • Expected downstream (post-cat) O2 sensor voltage: often relatively steady near ~0.4–0.6 V when closed-loop and cat working; should not be constantly >0.8 V
  • Upstream (pre-cat) O2 sensors normally oscillate ~0.1–0.9 V rapidly
  • High-voltage threshold that may set P0144: sustained sensor signal near or above ~0.8–1.0 V (varies by manufacturer)
  • Typical heater circuit resistance (sensor dependent): roughly 2–20 ohms; check manufacturer spec

Diagnostic algorithm

  1. Read and record freeze frame and pending codes; clear code and retest to confirm repeatability.
  2. Visual inspection: check sensor body, connector, wiring harness and ground points for damage, corrosion, or exposure to heat/oil/coolant.
  3. Backprobe the signal wire with the engine running: observe voltage with a scan tool or meter. If voltage is constantly high (~>0.8 V), suspect short to power or sensor stuck high.
  4. With ignition on (engine off) measure signal wire voltage; if ~12 V or near battery voltage, wiring is shorted to power — locate and repair short.
  5. Test heater circuit: with connector disconnected measure resistance between heater pins and check for battery voltage to heater circuit with ignition on; repair as needed.
  6. Wiggle test harness while monitoring signal to find intermittent opens/shorts.
  7. Compare upstream and downstream sensor behavior. If downstream mirrors upstream continuously high, check upstream issues (rich condition, injector problem, fuel pressure).
  8. Inspect for exhaust leaks or clogged/failed catalytic converter (backpressure test) if sensor readings are abnormal despite good wiring.
  9. If wiring and vehicle systems test good, replace the downstream O2 sensor; clear codes and road test to verify resolution.
  10. If problem persists after sensor replacement, suspect PCM fault and perform PCM-specific checks or consult manufacturer service information.

Likely causes

  • Damaged or shorted signal wiring to battery/ignition feed
  • Failed downstream O2 sensor (Bank 1 Sensor 3)
  • Connector corrosion or poor ground at sensor
  • Exhaust contamination or restrictive catalytic converter causing abnormal reading
  • Less likely: PCM internal fault

Fault status

⚠️ Status
ECM detected a persistently high voltage from the Bank 1 Sensor 3 oxygen sensor circuit, indicating the sensor signal is higher than expected or the circuit is shorted to a power source.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
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