Code
P0118
Generic
P — Powertrain
Engine Coolant Temperature Sensor 1 Circuit High
Views:
UK: 27
EN: 35
RU: 134
AI status
Completed
Completed
100%
Causes
- Open or high-resistance wiring in the ECT sensor circuit
- Corroded, loose, or damaged sensor connector
- Failed ECT (thermistor) sensor
- Poor or lost ground or reference supply to the sensor
- Faulty PCM/ECM driver or internal circuit fault
- Recent repairs or connector disturbance that damaged wiring
Symptoms
- Illuminated MIL / Check Engine Light
- Hard cold starts, extended warm-up, or rich running after start
- Poor fuel economy and possible rough idle
- Cooling fan inoperative or delayed (fans may not run when needed)
- Possible overheating if fans never engage or thermostat action is affected
What to check
- Retrieve freeze-frame and live data for coolant temperature with a scan tool
- Check for additional related codes (e.g., P0117, P0115, P0119)
- Visual inspection of sensor, connector, and wiring for damage or corrosion
- Backprobe sensor connector with ignition ON (engine OFF) to measure signal voltage and reference
- Measure sensor resistance at two known temps (cold and warm) and compare trend
- Check for proper reference voltage (typically ~5V) and good ground at harness
Signal parameters
- Typical reference voltage to sensor: ~5 V (varies by manufacturer)
- Normal ECT signal voltage: varies with temp (cold → higher voltage; hot → lower voltage)
- High-circuit fault typically: signal voltage near reference (>4.5 V) or open/infinite resistance
- Typical thermistor resistance: several kilo-ohms at ambient (drops as temperature rises) — consult vehicle spec
- Expected change: resistance should decrease as coolant temperature increases (negative temperature coefficient)
Diagnostic algorithm
- Verify presence of P0118 and note freeze-frame/conditions using a scan tool.
- Inspect sensor and harness for corrosion, bent pins, damage, or recent work that could have disturbed wiring.
- With ignition ON (engine OFF) backprobe the sensor signal wire: measure voltage between signal and ground. If voltage is at or near reference (≈ battery/5V) suspect open sensor or open to ground.
- Check reference supply at connector (should be ~5V with ignition ON). If reference missing, trace back to fuse/ECM supply.
- Check sensor ground continuity back to chassis/ECM ground. Repair any poor grounds.
- With sensor removed, measure sensor resistance at ambient and after warming (careful when hot). Resistance should decrease as temperature rises; if open or out of expected trend, replace the sensor.
- If wiring and sensor check good, perform continuity/resistance check between sensor connector and ECM pins to rule out open circuit or short.
- Wiggle test harness while monitoring live data for intermittent changes. Repair any intermittent wiring faults.
- If wiring and sensor are good but problem persists, consider substituting a known-good sensor. If still present, test PCM input circuitry or consult vehicle-specific service info for PCM tests.
- Clear codes and perform road/temperature test to confirm repair and that the code does not return.
Likely causes
- Broken/frayed wire between sensor and ECM (open circuit)
- Connector corrosion/dirty pins causing high resistance or open
- ECT sensor element failed open or out of range
- Blown fuse or interrupted 5V reference or sensor ground
- PCM input circuit failure (less common)
Fault status
Status
P0118 — ECT Sensor 1 Circuit High: sensor signal high or open circuit detected (ECM reading abnormally low coolant temp).
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
Workshop Manuals
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Workshop ManualAudi A3 (1997) – 1.6L 4-cylinder (2‑valve) Engine Mechanical Components Service Manual (AEH, AKL, APF) – Edition 07.2002
Workshop ManualAUDI A3 (2004) Workshop Manual — 2.0L FSI Turbo (4‑cyl, 4‑valve) Engine, Mechanics — Edition 03.2017
Workshop ManualAudi A3 2004 — Electrical System (Workshop Manual, Edition 02.2018)
Workshop ManualAudi A4 / A4 Cabriolet – 4.2 l V8 (5‑valve, timing chains) – Workshop Manual (Mechanics) – Edition 04.2007
Workshop ManualAudi A4 / A4 Cabriolet — Auxiliary Heater Workshop Manual (Edition 08.2004)
Workshop ManualAudi A4 / A4 Cabriolet (1.8T 4‑cyl turbo) — Motronic Injection & Ignition System Service Manual (Edition 01.2015)
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Workshop ManualAudi Servicing Manual — 7‑Speed Dual Clutch Transmission 0CJ / 0CL / 0CK / 0DN / 0DP / 0HL (Edition 05.2018)
Workshop ManualLAND ROVER 3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop ManualLand Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop ManualLand Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop ManualYour experience will help others
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Code
P0118
GWM
P — Powertrain
- High Engine Coolant Temperature Sensor
Views:
UK: 4
EN: 11
RU: 10
AI status
Completed
Completed
100%
Causes
- Open or high-resistance wiring in the ECT sensor circuit
- Corroded, loose, or damaged sensor connector
- Failed ECT (thermistor) sensor
- Poor or lost ground or reference supply to the sensor
- Faulty PCM/ECM driver or internal circuit fault
- Recent repairs or connector disturbance that damaged wiring
Symptoms
- Illuminated MIL / Check Engine Light
- Hard cold starts, extended warm-up, or rich running after start
- Poor fuel economy and possible rough idle
- Cooling fan inoperative or delayed (fans may not run when needed)
- Possible overheating if fans never engage or thermostat action is affected
What to check
- Retrieve freeze-frame and live data for coolant temperature with a scan tool
- Check for additional related codes (e.g., P0117, P0115, P0119)
- Visual inspection of sensor, connector, and wiring for damage or corrosion
- Backprobe sensor connector with ignition ON (engine OFF) to measure signal voltage and reference
- Measure sensor resistance at two known temps (cold and warm) and compare trend
- Check for proper reference voltage (typically ~5V) and good ground at harness
Signal parameters
- Typical reference voltage to sensor: ~5 V (varies by manufacturer)
- Normal ECT signal voltage: varies with temp (cold → higher voltage; hot → lower voltage)
- High-circuit fault typically: signal voltage near reference (>4.5 V) or open/infinite resistance
- Typical thermistor resistance: several kilo-ohms at ambient (drops as temperature rises) — consult vehicle spec
- Expected change: resistance should decrease as coolant temperature increases (negative temperature coefficient)
Diagnostic algorithm
- Verify presence of P0118 and note freeze-frame/conditions using a scan tool.
- Inspect sensor and harness for corrosion, bent pins, damage, or recent work that could have disturbed wiring.
- With ignition ON (engine OFF) backprobe the sensor signal wire: measure voltage between signal and ground. If voltage is at or near reference (≈ battery/5V) suspect open sensor or open to ground.
- Check reference supply at connector (should be ~5V with ignition ON). If reference missing, trace back to fuse/ECM supply.
- Check sensor ground continuity back to chassis/ECM ground. Repair any poor grounds.
- With sensor removed, measure sensor resistance at ambient and after warming (careful when hot). Resistance should decrease as temperature rises; if open or out of expected trend, replace the sensor.
- If wiring and sensor check good, perform continuity/resistance check between sensor connector and ECM pins to rule out open circuit or short.
- Wiggle test harness while monitoring live data for intermittent changes. Repair any intermittent wiring faults.
- If wiring and sensor are good but problem persists, consider substituting a known-good sensor. If still present, test PCM input circuitry or consult vehicle-specific service info for PCM tests.
- Clear codes and perform road/temperature test to confirm repair and that the code does not return.
Likely causes
- Broken/frayed wire between sensor and ECM (open circuit)
- Connector corrosion/dirty pins causing high resistance or open
- ECT sensor element failed open or out of range
- Blown fuse or interrupted 5V reference or sensor ground
- PCM input circuit failure (less common)
Fault status
Status
P0118 — ECT Sensor 1 Circuit High: sensor signal high or open circuit detected (ECM reading abnormally low coolant temp).
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
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Code
P0118
HUMMER
P — Powertrain
Engine Coolant Temperature (ECT) Sensor Circuit High Voltage
Views:
UK: 10
EN: 19
RU: 109
AI status
Completed
Completed
100%
Causes
- Open or high-resistance wiring in the ECT sensor circuit
- Corroded, loose, or damaged sensor connector
- Failed ECT (thermistor) sensor
- Poor or lost ground or reference supply to the sensor
- Faulty PCM/ECM driver or internal circuit fault
- Recent repairs or connector disturbance that damaged wiring
Symptoms
- Illuminated MIL / Check Engine Light
- Hard cold starts, extended warm-up, or rich running after start
- Poor fuel economy and possible rough idle
- Cooling fan inoperative or delayed (fans may not run when needed)
- Possible overheating if fans never engage or thermostat action is affected
What to check
- Retrieve freeze-frame and live data for coolant temperature with a scan tool
- Check for additional related codes (e.g., P0117, P0115, P0119)
- Visual inspection of sensor, connector, and wiring for damage or corrosion
- Backprobe sensor connector with ignition ON (engine OFF) to measure signal voltage and reference
- Measure sensor resistance at two known temps (cold and warm) and compare trend
- Check for proper reference voltage (typically ~5V) and good ground at harness
Signal parameters
- Typical reference voltage to sensor: ~5 V (varies by manufacturer)
- Normal ECT signal voltage: varies with temp (cold → higher voltage; hot → lower voltage)
- High-circuit fault typically: signal voltage near reference (>4.5 V) or open/infinite resistance
- Typical thermistor resistance: several kilo-ohms at ambient (drops as temperature rises) — consult vehicle spec
- Expected change: resistance should decrease as coolant temperature increases (negative temperature coefficient)
Diagnostic algorithm
- Verify presence of P0118 and note freeze-frame/conditions using a scan tool.
- Inspect sensor and harness for corrosion, bent pins, damage, or recent work that could have disturbed wiring.
- With ignition ON (engine OFF) backprobe the sensor signal wire: measure voltage between signal and ground. If voltage is at or near reference (≈ battery/5V) suspect open sensor or open to ground.
- Check reference supply at connector (should be ~5V with ignition ON). If reference missing, trace back to fuse/ECM supply.
- Check sensor ground continuity back to chassis/ECM ground. Repair any poor grounds.
- With sensor removed, measure sensor resistance at ambient and after warming (careful when hot). Resistance should decrease as temperature rises; if open or out of expected trend, replace the sensor.
- If wiring and sensor check good, perform continuity/resistance check between sensor connector and ECM pins to rule out open circuit or short.
- Wiggle test harness while monitoring live data for intermittent changes. Repair any intermittent wiring faults.
- If wiring and sensor are good but problem persists, consider substituting a known-good sensor. If still present, test PCM input circuitry or consult vehicle-specific service info for PCM tests.
- Clear codes and perform road/temperature test to confirm repair and that the code does not return.
Likely causes
- Broken/frayed wire between sensor and ECM (open circuit)
- Connector corrosion/dirty pins causing high resistance or open
- ECT sensor element failed open or out of range
- Blown fuse or interrupted 5V reference or sensor ground
- PCM input circuit failure (less common)
Fault status
Status
P0118 — ECT Sensor 1 Circuit High: sensor signal high or open circuit detected (ECM reading abnormally low coolant temp).
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
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+100 karma for a short comment :)
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Code
P0118
ISUZU
P — Powertrain
Engine Coolant Temperature Sensor Circuit High
Views:
UK: 18
EN: 26
RU: 115
AI status
Completed
Completed
100%
Causes
- Open or high-resistance wiring in the ECT sensor circuit
- Corroded, loose, or damaged sensor connector
- Failed ECT (thermistor) sensor
- Poor or lost ground or reference supply to the sensor
- Faulty PCM/ECM driver or internal circuit fault
- Recent repairs or connector disturbance that damaged wiring
Symptoms
- Illuminated MIL / Check Engine Light
- Hard cold starts, extended warm-up, or rich running after start
- Poor fuel economy and possible rough idle
- Cooling fan inoperative or delayed (fans may not run when needed)
- Possible overheating if fans never engage or thermostat action is affected
What to check
- Retrieve freeze-frame and live data for coolant temperature with a scan tool
- Check for additional related codes (e.g., P0117, P0115, P0119)
- Visual inspection of sensor, connector, and wiring for damage or corrosion
- Backprobe sensor connector with ignition ON (engine OFF) to measure signal voltage and reference
- Measure sensor resistance at two known temps (cold and warm) and compare trend
- Check for proper reference voltage (typically ~5V) and good ground at harness
Signal parameters
- Typical reference voltage to sensor: ~5 V (varies by manufacturer)
- Normal ECT signal voltage: varies with temp (cold → higher voltage; hot → lower voltage)
- High-circuit fault typically: signal voltage near reference (>4.5 V) or open/infinite resistance
- Typical thermistor resistance: several kilo-ohms at ambient (drops as temperature rises) — consult vehicle spec
- Expected change: resistance should decrease as coolant temperature increases (negative temperature coefficient)
Diagnostic algorithm
- Verify presence of P0118 and note freeze-frame/conditions using a scan tool.
- Inspect sensor and harness for corrosion, bent pins, damage, or recent work that could have disturbed wiring.
- With ignition ON (engine OFF) backprobe the sensor signal wire: measure voltage between signal and ground. If voltage is at or near reference (≈ battery/5V) suspect open sensor or open to ground.
- Check reference supply at connector (should be ~5V with ignition ON). If reference missing, trace back to fuse/ECM supply.
- Check sensor ground continuity back to chassis/ECM ground. Repair any poor grounds.
- With sensor removed, measure sensor resistance at ambient and after warming (careful when hot). Resistance should decrease as temperature rises; if open or out of expected trend, replace the sensor.
- If wiring and sensor check good, perform continuity/resistance check between sensor connector and ECM pins to rule out open circuit or short.
- Wiggle test harness while monitoring live data for intermittent changes. Repair any intermittent wiring faults.
- If wiring and sensor are good but problem persists, consider substituting a known-good sensor. If still present, test PCM input circuitry or consult vehicle-specific service info for PCM tests.
- Clear codes and perform road/temperature test to confirm repair and that the code does not return.
Likely causes
- Broken/frayed wire between sensor and ECM (open circuit)
- Connector corrosion/dirty pins causing high resistance or open
- ECT sensor element failed open or out of range
- Blown fuse or interrupted 5V reference or sensor ground
- PCM input circuit failure (less common)
Fault status
Status
P0118 — ECT Sensor 1 Circuit High: sensor signal high or open circuit detected (ECM reading abnormally low coolant temp).
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
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+100 karma for a short comment :)
Was this AI description helpful?
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Code
P0118
LAND ROVER
P — Powertrain
Engine Coolant Temperature Circuit High Input
Views:
UK: 6
EN: 16
RU: 96
AI status
Completed
Completed
100%
Causes
- Open or high-resistance wiring in the ECT sensor circuit
- Corroded, loose, or damaged sensor connector
- Failed ECT (thermistor) sensor
- Poor or lost ground or reference supply to the sensor
- Faulty PCM/ECM driver or internal circuit fault
- Recent repairs or connector disturbance that damaged wiring
Symptoms
- Illuminated MIL / Check Engine Light
- Hard cold starts, extended warm-up, or rich running after start
- Poor fuel economy and possible rough idle
- Cooling fan inoperative or delayed (fans may not run when needed)
- Possible overheating if fans never engage or thermostat action is affected
What to check
- Retrieve freeze-frame and live data for coolant temperature with a scan tool
- Check for additional related codes (e.g., P0117, P0115, P0119)
- Visual inspection of sensor, connector, and wiring for damage or corrosion
- Backprobe sensor connector with ignition ON (engine OFF) to measure signal voltage and reference
- Measure sensor resistance at two known temps (cold and warm) and compare trend
- Check for proper reference voltage (typically ~5V) and good ground at harness
Signal parameters
- Typical reference voltage to sensor: ~5 V (varies by manufacturer)
- Normal ECT signal voltage: varies with temp (cold → higher voltage; hot → lower voltage)
- High-circuit fault typically: signal voltage near reference (>4.5 V) or open/infinite resistance
- Typical thermistor resistance: several kilo-ohms at ambient (drops as temperature rises) — consult vehicle spec
- Expected change: resistance should decrease as coolant temperature increases (negative temperature coefficient)
Diagnostic algorithm
- Verify presence of P0118 and note freeze-frame/conditions using a scan tool.
- Inspect sensor and harness for corrosion, bent pins, damage, or recent work that could have disturbed wiring.
- With ignition ON (engine OFF) backprobe the sensor signal wire: measure voltage between signal and ground. If voltage is at or near reference (≈ battery/5V) suspect open sensor or open to ground.
- Check reference supply at connector (should be ~5V with ignition ON). If reference missing, trace back to fuse/ECM supply.
- Check sensor ground continuity back to chassis/ECM ground. Repair any poor grounds.
- With sensor removed, measure sensor resistance at ambient and after warming (careful when hot). Resistance should decrease as temperature rises; if open or out of expected trend, replace the sensor.
- If wiring and sensor check good, perform continuity/resistance check between sensor connector and ECM pins to rule out open circuit or short.
- Wiggle test harness while monitoring live data for intermittent changes. Repair any intermittent wiring faults.
- If wiring and sensor are good but problem persists, consider substituting a known-good sensor. If still present, test PCM input circuitry or consult vehicle-specific service info for PCM tests.
- Clear codes and perform road/temperature test to confirm repair and that the code does not return.
Likely causes
- Broken/frayed wire between sensor and ECM (open circuit)
- Connector corrosion/dirty pins causing high resistance or open
- ECT sensor element failed open or out of range
- Blown fuse or interrupted 5V reference or sensor ground
- PCM input circuit failure (less common)
Fault status
Status
P0118 — ECT Sensor 1 Circuit High: sensor signal high or open circuit detected (ECM reading abnormally low coolant temp).
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
Workshop Manuals
Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop ManualLand Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop ManualLand Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop ManualYour experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
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Code
P0118
MITSUBISHI
P — Powertrain
Engine coolant TEMP.sensor high
Views:
UK: 7
EN: 19
RU: 105
AI status
Completed
Completed
100%
Causes
- Open or high-resistance wiring in the ECT sensor circuit
- Corroded, loose, or damaged sensor connector
- Failed ECT (thermistor) sensor
- Poor or lost ground or reference supply to the sensor
- Faulty PCM/ECM driver or internal circuit fault
- Recent repairs or connector disturbance that damaged wiring
Symptoms
- Illuminated MIL / Check Engine Light
- Hard cold starts, extended warm-up, or rich running after start
- Poor fuel economy and possible rough idle
- Cooling fan inoperative or delayed (fans may not run when needed)
- Possible overheating if fans never engage or thermostat action is affected
What to check
- Retrieve freeze-frame and live data for coolant temperature with a scan tool
- Check for additional related codes (e.g., P0117, P0115, P0119)
- Visual inspection of sensor, connector, and wiring for damage or corrosion
- Backprobe sensor connector with ignition ON (engine OFF) to measure signal voltage and reference
- Measure sensor resistance at two known temps (cold and warm) and compare trend
- Check for proper reference voltage (typically ~5V) and good ground at harness
Signal parameters
- Typical reference voltage to sensor: ~5 V (varies by manufacturer)
- Normal ECT signal voltage: varies with temp (cold → higher voltage; hot → lower voltage)
- High-circuit fault typically: signal voltage near reference (>4.5 V) or open/infinite resistance
- Typical thermistor resistance: several kilo-ohms at ambient (drops as temperature rises) — consult vehicle spec
- Expected change: resistance should decrease as coolant temperature increases (negative temperature coefficient)
Diagnostic algorithm
- Verify presence of P0118 and note freeze-frame/conditions using a scan tool.
- Inspect sensor and harness for corrosion, bent pins, damage, or recent work that could have disturbed wiring.
- With ignition ON (engine OFF) backprobe the sensor signal wire: measure voltage between signal and ground. If voltage is at or near reference (≈ battery/5V) suspect open sensor or open to ground.
- Check reference supply at connector (should be ~5V with ignition ON). If reference missing, trace back to fuse/ECM supply.
- Check sensor ground continuity back to chassis/ECM ground. Repair any poor grounds.
- With sensor removed, measure sensor resistance at ambient and after warming (careful when hot). Resistance should decrease as temperature rises; if open or out of expected trend, replace the sensor.
- If wiring and sensor check good, perform continuity/resistance check between sensor connector and ECM pins to rule out open circuit or short.
- Wiggle test harness while monitoring live data for intermittent changes. Repair any intermittent wiring faults.
- If wiring and sensor are good but problem persists, consider substituting a known-good sensor. If still present, test PCM input circuitry or consult vehicle-specific service info for PCM tests.
- Clear codes and perform road/temperature test to confirm repair and that the code does not return.
Likely causes
- Broken/frayed wire between sensor and ECM (open circuit)
- Connector corrosion/dirty pins causing high resistance or open
- ECT sensor element failed open or out of range
- Blown fuse or interrupted 5V reference or sensor ground
- PCM input circuit failure (less common)
Fault status
Status
P0118 — ECT Sensor 1 Circuit High: sensor signal high or open circuit detected (ECM reading abnormally low coolant temp).
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
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👍 Like
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0
Send to email