P0C1D

Code

Generic P — Powertrain

Electric/Auxiliary Transmission Fluid Pump Control Module Internal Temperature Sensor Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 26 EN: 37 RU: 27

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or short in the temperature sensor circuit (wiring or connector)
Corroded, damaged, or loose connector at the pump control module
Failed internal temperature sensor inside the pump control module
Poor ground or missing reference voltage to the sensor
Water intrusion or contamination of connector/sensor
Intermittent contact due to broken wire or pin

Symptoms

Transmission or pump warning light (transmission/EV system warning)
Reduced pump performance or disabled auxiliary pump (reduced cooling/pressure)
Transmission overheating or erroneous temperature readings
Limited drive or limp mode to protect transmission
Stored and/or intermittent DTC P0C1D

What to check

Read freeze frame and live data for pump temperature sensor value and associated signals
Visual inspection of pump module connector and wiring for corrosion, damage, or water
Verify related fuses and main power/ground to pump control module
Backprobe sensor signal, reference voltage, and ground with ignition ON and compare to expected
Wiggle test harness while monitoring sensor signal for intermittent changes
Measure sensor resistance with connector disconnected (if external) and compare to temperature chart if available

Signal parameters

Sensor signal voltage typically within 0.1–4.8 V depending on temperature (varies by design)
Typical mid-range ambient temp often near ~2.5 V on many NTC sensors (manufacturer dependent)
Sensor resistance expected to change with temperature (NTC: higher resistance at low temp, lower at high temp). Typical order of magnitude: kilo-ohms (check vehicle spec)
Reference voltage usually 5 V or ignition voltage; ground should be near 0 V
Intermittent or rapidly changing values indicate wiring/connector issues

Diagnostic algorithm

Read DTCs and freeze frame; record sensor voltage/temperature, ignition state, and conditions when fault set.
Perform a visual inspection of the pump module connector and harness for corrosion, pin damage, heat, or water intrusion.
With ignition ON (engine off if applicable) backprobe the sensor signal, reference voltage, and ground at the module connector. Confirm reference voltage (often ~5 V), ground continuity, and that signal is within expected range.
If signal is out of range, disconnect the connector and measure sensor resistance (if sensor is external and serviceable). Compare resistance to expected values for ambient temperature. If internal sensor, proceed to next steps.
Perform a wiggle/intermittent test on wiring while watching live data to reproduce the fault; repair any intermittent wiring or connector problems found.
Check for shorts to battery or ground on the signal circuit (ohm or voltage tests). Repair/replace wiring as needed.

Likely causes

Corroded connector or pin at the pump module causing high resistance or intermittent signal
Damaged harness (chafed wire, broken conductor) between sensor and module
Internal sensor failure inside the pump control module (most likely if wiring checks good)
Short to battery or ground on the sensor signal causing out-of-range voltage

Fault status

⚠️ Status

The pump control module reports its internal temperature sensor signal is outside the expected range or is performing abnormally. Inspect wiring/connectors and verify module power, ground, and sensor signal before replacing the module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours