P2925

Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 4

P2925 is a generic OBD-II powertrain diagnostic trouble code: Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 4. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2925
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
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What P2925 means

P2925 is set when the ECM detects that the signal from exhaust gas temperature (EGT) sensor 4 on bank 1 is above the maximum expected voltage or temperature threshold. Sensor 4 in the EGT sensor numbering convention is located downstream in the exhaust aftertreatment system, typically after the diesel particulate filter (DPF) or selective catalytic reduction (SCR) catalyst, depending on the vehicle configuration.

A circuit-high condition on an EGT sensor most commonly results from an open signal wire or open sensor element, causing the ECM input to float toward reference voltage. It can also be caused by a sensor whose internal resistance has increased beyond specification, or by wiring damage that creates an unintended connection to a voltage source. Because the ECM uses EGT4 readings to monitor aftertreatment temperatures for regeneration control and component protection, a high fault can disable DPF active regeneration or SCR dosing strategies.

The diagnostic approach should begin with live-data observation to confirm whether the signal is stuck at a fixed high value or is intermittent. Wiring integrity from the sensor to the ECM should be verified before sensor replacement is considered. Comparing the reading to other EGT sensors during engine operation can help confirm whether one sensor is clearly out of family.

Common causes

Most-frequently reported root causes when P2925 is logged.

  • 1
    Open circuit in the EGT sensor signal wire causing the input to float high.
  • 2
    Failed EGT sensor with an open or high-resistance internal element.
  • 3
    Corroded or damaged sensor connector allowing moisture ingress.
  • 4
    Wiring harness chafing or break near the high-temperature exhaust environment.
  • 5
    Short to voltage on the sensor signal circuit.
  • 6
    Sensor exceeding its thermal rating due to abnormal exhaust temperatures.
  • 7
    Poor ECM connector contact on the EGT sensor input pin.

Symptoms drivers notice

MIL illuminated.
DPF regeneration may be disabled or altered.
Possible SCR dosing strategy changes affecting NOx emissions.
Scan tool shows EGT sensor 4 reading stuck at an implausibly high fixed value.
No significant driveability symptoms in most cases.

How to diagnose P2925

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and note freeze-frame data; check for companion EGT or aftertreatment codes.
  2. 2
    Observe EGT sensor 4 live data and compare it to other EGT sensor readings to confirm an out-of-family value.
  3. 3
    Inspect the sensor wiring and connector for heat damage, chafing, or corrosion in the exhaust area.
  4. 4
    Measure supply and ground at the sensor connector to confirm circuit integrity.
  5. 5
    Check signal wire continuity and test for a short to voltage with the sensor disconnected.
  6. 6
    Measure the sensor element resistance at ambient temperature and compare to specification.
  7. 7
    Replace the EGT sensor if circuit wiring tests pass and the sensor element is out of specification.

Related powertrain codes

Frequently asked questions

Where exactly is EGT sensor 4 bank 1 located?

Sensor numbering increases downstream from the engine; sensor 4 is typically the most downstream sensor, often after the DPF or SCR, though exact placement varies by manufacturer.

Is P2925 serious?

It is an emissions-system fault that is not immediately dangerous to drive with but can disable aftertreatment strategies, increasing emissions and potentially damaging the DPF or SCR over time.

Can I reset P2925 without replacing anything?

If caused by an intermittent connector issue, cleaning and reseating the connector may resolve it, but a permanent repair requires fixing the root cause.

Does P2925 cause a DPF warning light?

It may trigger both the MIL and a separate DPF or aftertreatment warning depending on the vehicle's instrument cluster configuration.

Disabling P2925 in software

RaceTune can permanently disable P2925 — 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.

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.

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