P27BE

EGR Cooler Bypass Control Circuit High

P27BE is a generic OBD-II powertrain diagnostic trouble code: EGR Cooler Bypass Control Circuit High. 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
P27BE
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
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What P27BE means

P27BE is stored when the PCM detects a higher-than-expected voltage on the control circuit for the EGR cooler bypass valve actuator. The EGR cooler bypass valve directs exhaust gas either through the EGR cooler (for normal warm-running operation to reduce NOx) or around it (bypassing the cooler) during cold starts to accelerate engine warm-up and reduce condensation-related corrosion in the EGR circuit.

A high-circuit condition on the bypass control means the control signal or feedback voltage exceeds the expected range. This can occur due to a short to power in the control wiring, a seized or jammed bypass actuator causing driver circuit overload, or an internal fault in the EGR bypass control solenoid that pulls the circuit high. The module may disable the bypass function and default the valve to a fixed position.

With the bypass stuck or uncontrolled, cold-start EGR management is compromised, which can affect cold-idle emissions and engine warm-up behavior. In most cases there is no significant hot-running driveability symptom, but the MIL will remain illuminated and EGR-related emissions may increase.

Common causes

Most-frequently reported root causes when P27BE is logged.

  • 1
    Short to voltage in the EGR cooler bypass actuator control wiring.
  • 2
    Failed EGR cooler bypass solenoid with an internally shorted coil pulling circuit high.
  • 3
    EGR bypass valve mechanically seized, overloading the driver circuit.
  • 4
    Damaged or corroded connector providing unintended voltage path to the control line.
  • 5
    PCM EGR bypass driver circuit fault producing elevated output voltage.
  • 6
    Water intrusion into the bypass actuator wiring connector.

Symptoms drivers notice

MIL illuminated.
EGR cooler bypass may be stuck in one position (either always bypassing or always cooling).
Cold-start rough idle or extended warm-up time if bypass is stuck closed (always cooling).
Possible EGR cooler condensation issues if bypass is stuck open during cold operation.
Generally no hot-running driveability complaint.

How to diagnose P27BE

A typical diagnostic flow when this code is present.

  1. 1
    Scan for all DTCs and freeze frame; note any companion EGR system or emissions codes.
  2. 2
    Inspect the EGR cooler bypass actuator connector and wiring for shorts to power, chafing, or corrosion.
  3. 3
    With the actuator commanded off, measure voltage on the control circuit; unexpected voltage indicates a short to power.
  4. 4
    Measure the bypass solenoid coil resistance and compare to specification; very low resistance suggests an internal short.
  5. 5
    Operate the bypass actuator via scan tool output controls and verify physical movement if accessible.
  6. 6
    Check the PCM connector terminals for damage or pushed-back pins on the EGR bypass driver circuit.
  7. 7
    Repair wiring or replace the bypass solenoid as indicated; verify circuit voltage after repair.

Vehicles where we've handled P27BE

Platforms in our catalogue with confirmed P27BE coverage.

BMW 320D
2016

Related powertrain codes

Frequently asked questions

What does the EGR cooler bypass valve actually do?

It routes exhaust gas around the EGR cooler during cold starts so warmer gas recirculates, helping the engine warm up faster and reducing moisture condensation in the EGR path.

Is P27BE a serious fault?

It sets the MIL and affects cold-start emissions management, but hot-running operation is usually unaffected. It should be repaired to maintain emissions compliance and prevent cooler condensation damage.

Can I ignore P27BE in summer?

Cold-start effects are less noticeable in warm climates, but the MIL will remain on and emissions testing may fail. The fault should be repaired regardless of season.

How do I tell if the bypass valve is stuck versus the electrical circuit is at fault?

Confirm the electrical circuit first by checking voltage and resistance. Then try commanding the valve via scan tool and observe physical response or actuator current draw to determine if the valve moves.

Disabling P27BE in software

RaceTune can permanently disable P27BE — 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.

ECUs with a P27BE disable in our catalogue

Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.

  • Bosch EDC17C50 verified 1 software version

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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