P2926

Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 4

P2926 is a generic OBD-II powertrain diagnostic trouble code: Exhaust Gas Temperature Sensor Circuit Intermittent 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
P2926
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
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What P2926 means

P2926 is logged when the ECM detects an intermittent signal fault from exhaust gas temperature sensor 4 on bank 1. Unlike a continuous high or low circuit code, an intermittent designation indicates that the sensor signal drops out or behaves erratically at irregular intervals, often correlating with vibration, thermal cycling, or connector flex rather than a hard electrical failure.

EGT sensor 4 is located downstream in the exhaust aftertreatment system and its signal is used to manage DPF regeneration cycles, SCR catalyst efficiency monitoring, and component over-temperature protection. An intermittent dropout in this signal can lead to poorly timed regeneration events or false over-temperature shutdowns, even though the sensor appears functional during a static diagnostic check.

Diagnosing intermittent faults requires duplicating the condition. Technicians should wiggle-test the wiring harness and connector while monitoring the live EGT4 signal on a scan tool, looking for signal dropouts. Thermal cycling by running the engine to operating temperature while observing the signal can reveal heat-related intermittents. Connector inspection for pin fretting corrosion or micro-damage is especially important in the high-vibration exhaust environment.

Common causes

Most-frequently reported root causes when P2926 is logged.

  • 1
    Intermittent open circuit due to a cracked or chafed signal wire that makes and breaks contact.
  • 2
    Fretting corrosion on sensor connector pins causing momentary loss of contact.
  • 3
    Connector that is partially seated or has a loose locking tab.
  • 4
    Internal sensor element that breaks contact intermittently under thermal expansion.
  • 5
    Vibration-induced wiring fault near the exhaust mounting points.
  • 6
    Heat-damaged wiring insulation causing intermittent shorts under load.
  • 7
    ECM connector pin with high contact resistance that drifts under temperature.

Symptoms drivers notice

MIL illuminated, often with an intermittent history.
Unpredictable DPF regeneration behavior or unexpected regeneration events.
Scan tool shows EGT sensor 4 occasionally spiking or dropping to an implausible value.
Possible aftertreatment warning messages that come and go.
No consistent driveability complaint from the driver.

How to diagnose P2926

A typical diagnostic flow when this code is present.

  1. 1
    Read and record all DTCs and review the fault frequency counter if supported by the scan tool.
  2. 2
    Monitor EGT sensor 4 live data while performing a thorough wiggle test on the harness and connector.
  3. 3
    Run the engine to full operating temperature and observe whether the dropout correlates with heat soak.
  4. 4
    Inspect the connector for fretting corrosion, bent pins, or a loose locking mechanism.
  5. 5
    Check the harness routing for contact with exhaust components that could cause heat or vibration damage.
  6. 6
    Repair any wiring or connector defects found and retest under the same conditions that triggered the fault.
  7. 7
    Replace the EGT sensor only if all wiring repairs have been made and the intermittent fault persists.

Related powertrain codes

Frequently asked questions

Why does my scan tool show no fault when I check it, but the MIL stays on?

Intermittent faults may not be active at the time of scanning; the ECM stores them as historical faults even after the signal returns to normal.

Is P2926 different from P2925?

Yes, P2925 is a continuous circuit-high fault while P2926 specifically identifies the fault as intermittent in nature.

Can a poor exhaust sensor bung cause this code?

If the sensor is loose in its bung and vibrates, it could cause intermittent connector or element contact faults that trigger P2926.

How do I confirm the fault is fixed after a connector repair?

Drive the vehicle through the conditions that originally triggered the fault and monitor the sensor live data to confirm stable readings before clearing codes.

Disabling P2926 in software

RaceTune can permanently disable P2926 — 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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