What causes fault code P02E4?

• Most likely: Faulty Intake Air Flow Control Actuator (internal open coil) • Likely: Damaged wiring or chafed wires in the engine harness • Possible: Oxidized or loose connectors at the throttle body • Possible: Blown fuse for the actuator power supply • Rare: Faulty Engine Control Unit (ECU)

Powertrain (Engine & Gearbox)Standard EOBD

P02E4 - Diesel Intake Air Flow Control 'A' Circuit Open

Q: What are the symptoms of fault code P02E4?

• Check engine light (MIL) illuminated • Engine shakes excessively during shutdown (anti-shudder fail) • Reduced engine power (Limp mode may be triggered) • DPF regeneration issues • Increased emissions and potential black smoke during acceleration

Q: How do you fix fault code P02E4?

STEP 1: Inspect the connector to the intake air flow actuator for corrosion or loose pins. Clean if necessary. STEP 2: Measure power supply to the actuator with ignition ON. Should typically be 12V. Check fuses if power is missing. STEP 3: Check ground connection and perform a resistance test on the actuator motor (between terminals). A reading of 'O.L' indicates an internal open circuit. STEP 4: Use a diagnostic tool to perform a bidirectional actuator test. Check the PWM signal (Duty-cycle) with an oscilloscope if available. STEP 5: If wiring and power are OK but the actuator remains unresponsive, replace the Throttle Body Actuator and perform any required adaptation/relearn procedures.

Last updated:1 February 2026

Related:Intake Air Flow Actuator, Throttle Body, Engine Control Module (ECM), EGR System, DPF System

System

Powertrain (Engine & Gearbox)

Related Fault Codes

P0200

Injector Circuit Malfunction

P0201

Cylinder 1 Injector Circuit Open

P0202

Injector Circuit - Cylinder 2 - Malfunction

P0203

Injector Circuit - Cylinder 3

Technical Description

The P02E4 fault code is set when the Engine Control Unit (ECU) detects an open circuit in the control circuit of the Diesel Intake Air Flow Control Actuator 'A'. In diesel engines, this throttle plate is used to restrict airflow to facilitate EGR flow, manage DPF regeneration temperatures, and prevent engine shudder during shutdown. An 'open circuit' means there is no electrical continuity in the signal or power line to the actuator, preventing the ECU from controlling the throttle plate position. The system will typically default to a fully open failsafe position.

Possible Causes

Faulty Intake Air Flow Control Actuator (internal open coil)

Damaged wiring or chafed wires in the engine harness

Oxidized or loose connectors at the throttle body

Blown fuse for the actuator power supply

Faulty Engine Control Unit (ECU)

Symptoms

Check engine light (MIL) illuminated

Engine shakes excessively during shutdown (anti-shudder fail)

Reduced engine power (Limp mode may be triggered)

DPF regeneration issues

Increased emissions and potential black smoke during acceleration

Do you also have
other fault codes?

See how P02E4 connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.

Analyze multiple codes

P02E4 - Diesel Intake Air Flow Control 'A' Circuit Open

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have
other fault codes?

P02E4 - Diesel Intake Air Flow Control 'A' Circuit Open

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have other fault codes?

Do you also have
other fault codes?