P041C

Gas Recirculation Temperature Sensor B Circuit Low

P041C is a generic OBD-II powertrain diagnostic trouble code: Gas Recirculation Temperature Sensor B Circuit Low. It is logged by the engine control unit when the egr monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P041C
Group
Powertrain
System
EGR
Severity
Warning (MIL on)
Need P041C disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P041C means

P041C is set when the engine control module detects an abnormally low voltage on the exhaust gas recirculation (EGR) temperature sensor B signal circuit. EGR temperature sensors are negative-temperature-coefficient (NTC) resistors: the ECM supplies a 5-volt reference and a ground, and the returned voltage reflects gas temperature. Higher temperature lowers resistance and pulls the signal voltage down. When the reported resistance or voltage stays below the calibrated minimum for a set time, the ECM interprets the reading as impossibly low and stores P041C.

Sensor B is typically the second EGR temperature sensor in the system, often positioned at the EGR cooler outlet or the opposite bank from sensor A, depending on the manufacturer. A low circuit reading usually means the signal wire is shorted to ground, the sensor element has failed internally, or the connector is contaminated.

Because the fault is electrical and thermal, diagnosis focuses on separating a bad sensor from harness or connector problems. The MIL is illuminated and EGR temperature-based strategies may default to a substitute value, but the engine generally still runs. Left unrepaired, incorrect EGR temperature data can affect EGR flow control and raise NOx emissions.

Common causes

Most-frequently reported root causes when P041C is logged.

  • 1
    Short to ground on the EGR temperature sensor B signal circuit.
  • 2
    Failed EGR temperature sensor B with an internally shorted element reading falsely low.
  • 3
    Corroded or moisture-contaminated connector creating a low-resistance path to ground.
  • 4
    Chafed harness wiring contacting chassis ground near the exhaust.
  • 5
    Open or high resistance in the sensor ground reference affecting the reported value.
  • 6
    Heat damage to the sensor or its wiring insulation from exhaust proximity.
  • 7
    Faulty ECM sensor input circuit (rare, verify wiring and sensor first).

Symptoms drivers notice

Malfunction indicator lamp illuminated with P041C stored.
Scan tool shows an implausibly low or maximum EGR temperature reading for sensor B.
Possible reduced or altered EGR operation as the ECM uses a default value.
Slightly elevated NOx emissions leading to emissions test failure.
Usually no obvious driveability change in mild cases.

How to diagnose P041C

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and review freeze-frame data for the conditions present when the code set.
  2. 2
    View live data for the EGR temperature sensor B value and compare it to sensor A and actual engine state.
  3. 3
    Inspect the sensor connector and harness near the exhaust for heat damage, corrosion, or moisture.
  4. 4
    With the key on, measure the signal voltage at the sensor connector; a value stuck near zero indicates a short to ground.
  5. 5
    Disconnect the sensor and recheck the signal wire; if voltage rises toward reference, the sensor is faulty.
  6. 6
    If voltage stays low with the sensor unplugged, trace the signal wire for a short to ground.
  7. 7
    Replace the EGR temperature sensor B only after wiring and ground checks are confirmed good.

Vehicles where we've handled P041C

Platforms in our catalogue with confirmed P041C coverage.

BMW 320D
2016

Related powertrain codes

Frequently asked questions

What kind of sensor is the EGR temperature sensor B?

It is typically a temperature-sensitive resistor (thermistor) fed a reference voltage and ground by the ECM, whose resistance changes with exhaust gas temperature.

Does a low code mean the sensor reads cold or hot?

A low-voltage circuit fault usually corresponds to abnormally low measured resistance, which the ECM interprets as an out-of-range signal rather than a real temperature.

Can moisture in the connector cause P041C?

Yes; water or corrosion can create a low-resistance path to ground that pulls the signal voltage below the valid threshold.

Is it safe to keep driving with P041C?

The vehicle usually drives normally, but EGR temperature control is degraded and NOx emissions can rise, so the fault should be repaired.

Disabling P041C in software

RaceTune can permanently disable P041C — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECU families we can disable P041C on

We hold the DaVinci A2L disable definitions for these families, so the exact P041C path and mask addresses are mapped. verified marks a confirmed disable definition. We support many more — upload your file and our identifier will match it automatically.

  • Bosch EDC17C50 verified
  • Bosch EDC17C56 verified
  • Bosch EDC17C66 verified
  • Bosch EDC17CP57 verified
  • Bosch MD1CP002 verified
  • Bosch MD1CS001 verified

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P041C in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file