P1185

Code

Other P — Powertrain

FTS High - Fuel Pump Temperature Sensor High

Brand: Other

Type: P — Powertrain

Views: UK: 42 EN: 58 RU: 48

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Page language: EN

Causes

Open circuit in sensor wiring (broken wire, connector not seated)
Short to battery voltage in sensor circuit
Corroded or damaged sensor connector or terminals
Faulty fuel pump temperature sensor or in-tank pump module
Faulty ground or 5V/ reference supply from ECM
ECM/PCM internal fault (rare)

Symptoms

Stored P1185 (FTS circuit high) trouble code and MIL illumination
Possible incorrect fuel temperature readings in live data
Possible fuel system faults or limp-home behavior on some vehicles
No driveability symptoms on many vehicles (code only)
Fuel level or other tank-sensor related oddities if harness damaged

What to check

Read and record freeze frame and live data for fuel pump temperature and related sensors
Verify other codes present (fuel pump, fuel level, power/ground circuits)
Visually inspect fuel tank area, wiring harness, and connectors for damage/corrosion
Check connector pins for corrosion, bent pins, or pushed-out terminals
Verify reference voltage (usually 5 V) and ground at the sensor connector with ignition on
Backprobe sensor with multimeter/scan tool to observe live voltage/resistance

Signal parameters

Sensor type: typically an NTC thermistor integrated in pump/sender (resistance falls as temperature rises)
Circuit voltage: uses vehicle reference (commonly 5 V); sensor returns a varying voltage to ECM (0–5 V range)
Expected behavior: voltage/resistance should change smoothly with temperature (no open/short).
High circuit condition: voltage stuck near reference/battery voltage or resistance reading open/high beyond expected range
Exact resistance/voltage specs vary by manufacturer — consult vehicle OEM data before replacing parts

Diagnostic algorithm

Retrieve freeze-frame and pending codes; note patterns and other related tank or sensor codes.
Perform a thorough visual inspection of the fuel tank wiring, harness grommet, and connector at the pump module for corrosion, water intrusion, or rodent damage.
With ignition ON (engine OFF), backprobe the FTS connector: verify reference voltage from ECM and good ground. If reference voltage missing, diagnose ECM fuse/connector and wiring to ECM.
Measure sensor voltage while varying tank temperature if possible (warm the tank slightly or compare cold vs warm readings) and watch live data for sensible change. An unchanging high voltage indicates open/short-to-voltage.
If accessible, disconnect sensor connector and measure sensor resistance to ground; compare to OEM spec. If resistance reads open/infinite or far above spec, sensor/module likely bad.
Check continuity and for short-to-battery between sensor signal and battery; check for shorts to ground where appropriate.
Wiggle harness and connectors while monitoring live data to reproduce intermittent faults.
If wiring and connector pass tests but sensor readings are out-of-spec, replace the fuel pump module or the sensor (as applicable).
After repair, clear codes and road-test or cycle ignition to confirm code does not return. If it does, proceed to ECM/PCM diagnostics with OEM procedures.

Likely causes

Corroded/damaged connector or wiring at fuel pump module
Open or short in the sensor harness (broken wire or chafing)
Failed fuel pump temperature sensor inside pump module
Poor ground or missing reference voltage from ECM
ECM/PCM fault (least likely)

Fault status

⚠️ Status

FTS Circuit High Input — Fuel Pump Temperature Sensor voltage/resistance higher than expected. Check wiring, connector, sensor, and ECM reference/ground.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours