Code
P0183
HUMMER
P — Powertrain
Fuel Temperature Sensor Circuit High Voltage
AI status
Completed
Completed
100%
Causes
- Open, shorted, or damaged fuel temperature sensor wiring or connector
- Short to battery voltage or reference supply on the sensor signal circuit
- Corroded or loose connector at the sensor or fuel pump module
- Failed fuel temperature sensor (thermistor)
- Poor or missing ground from sensor circuit
- PCM or instrument cluster electrical fault (rare)
Symptoms
- Check Engine Light (MIL) on
- Incorrect or erratic fuel temperature readings in live data (very high value)
- Hard start, rough idle or poor running under some conditions (fuel trim affected)
- Reduced fuel economy or increased emissions
- Possible limp-in fuel strategy or reduced performance if PCM limits operation
What to check
- Read freeze-frame and stored data with an OBD-II scanner—note fuel temperature value and conditions when code set
- Monitor live data fuel temperature and compare to ambient/engine temps
- Check for related codes (fuel rail pressure, fuel pump, temp sensors)
- Visually inspect wiring and connectors at fuel pump module/in-tank sensor for corrosion, damage, or fuel intrusion
- Backprobe the sensor connector with key ON (engine OFF) and measure signal voltage, reference voltage, and ground
- Measure sensor resistance out of circuit at known ambient temperature and compare to specification if available
Signal parameters
- Typical signal voltage range: ~0.1–4.9 V (varies by vehicle); high-voltage fault often triggered when signal approaches supply voltage (~4.8–5.0 V)
- Reference voltage (sensor supply): commonly 5 V from PCM (verify on vehicle)
- Sensor type: usually an NTC thermistor—resistance decreases as temperature rises (resistance range varies by OEM)
- Typical resistance example (vehicle-specific): at 20°C often in the kilohm range (consult OEM spec sheet for exact values)
- Connector: usually 2 or 3 wires (signal, ground, and sometimes a reference)
Diagnostic algorithm
- Connect a quality OBD-II scanner. Read P0183, freeze-frame and live fuel temperature value. Note when code set (cold/warm/start conditions).
- Visually inspect harness and connector at the fuel pump/in-tank module for corrosion, pin push-out, fuel intrusion or damage. Repair as needed.
- With ignition ON (engine OFF), backprobe the sensor connector: verify reference voltage (typically ~5 V), verify good ground, and measure signal voltage. Record values.
- If signal voltage is at or near reference/battery voltage, disconnect the sensor and measure open-circuit voltage at the PCM connector to check for short to voltage on the harness.
- Remove sensor (or access module) and measure sensor resistance at ambient temperature. Compare to OEM specification or to a known-good sensor. If resistance indicates open/short or out of range, replace sensor.
- Check continuity between sensor ground and chassis ground. Check for shorts between signal wire and power supply with an ohmmeter (engine off, battery disconnected if needed).
- Repair or replace damaged wiring, connectors or sensor. Use dielectric grease on fuel-side connectors if recommended by OEM.
- Clear codes, perform key-on and start cycles, and verify live data. Road test to confirm code does not return. If code persists after wiring and sensor verified, test/replace PCM or consult manufacturer-specific diagnostics.
Likely causes
- Failed fuel temperature sensor
- Short to 5 V/reference or battery voltage on sensor signal wire
- Open or corroded connector at the fuel pump module or inline connector
- Bad ground at fuel tank/module
- Wiring harness chafed and contacting power source
Fault status
Status
P0183 — Fuel Temperature Sensor Circuit High Voltage. The PCM detected a fuel temperature sensor signal voltage higher than expected (near supply voltage). This indicates an electrical fault (short to voltage, failed sensor, bad connector/wiring) or, less commonly, PCM error. The fault may affect fueling calculations and emissions.
Repair difficulty: Medium
Diagnostic time: 0.5–2.0 hours
Similar codes
Repair manuals
Manual library for HUMMER
138
Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
-
HUMMER: 2009
-
HUMMER: 2008
-
HUMMER: 2007
-
HUMMER: 2005
-
HUMMER: 2004
-
HUMMER: 2000
-
HUMMER: 1999
-
HUMMER: 1994
-
HUMMER: 1993
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email