P004E Turbo / Supercharger Boost Control Circuit Loop Intermittent

P004E Turbo / Supercharger Boost Control Circuit Loop Intermittent

OBD-II DTC Datasheet

Turbocharger / supercharger boost control circuit "A" unstable / unstable

What does this mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to OBD-II equipped vehicles that have a supercharger or turbocharger (Ford Powerstroke, Chevrolet GMC Duramax, Toyota, Dodge, Jeep, Chrysler, VW, etc.) . D.). Although general, specific repair steps may differ depending on the brand / model.

Turbochargers and superchargers are air pumps that force air into an engine to increase power. The superchargers are driven from the engine crankshaft by a belt, while the turbochargers are driven by the engine exhaust gases.

Many modern turbocharged vehicles use a so-called variable geometry turbocharger (VGT). This type of turbocharger has adjustable blades around the outside of the turbine that can be opened and closed to change the amount of boost pressure. This allows the turbo to be controlled independently of the engine speed. The vanes usually open when the engine is under light load and open when the load increases. The blade position is controlled by the powertrain control module (PCM), usually via an electronic control solenoid or motor. The position of the turbocharger is determined using a special position sensor.

On vehicles that use a traditional fixed displacement turbocharger or supercharger, boost is controlled through a wastegate or wastegate. This valve opens to release the boost pressure. The PCM monitors this system with a boost pressure sensor.

For this DTC, "A" indicates a problem in a portion of the system circuit and not a specific symptom or component.

Code P004E is set when the PCM detects an intermittent or intermittent problem with the boost control solenoid, whether the engine is using VGT turbocharging or a traditional turbocharger / supercharger.

One type of turbocharger boost control solenoid valve:

Associated Turbo / Supercharger Engine DTCs:

• P0045 Turbocharger / Supercharger Boost Control «A» Circuit / Open
• P0046 Turbocharger / Supercharger Boost Control "A" Circuit Range / Performance
• P0047 Turbocharger / Supercharger Boost Control «A» Circuit Low
• P0048 Turbocharger / Supercharger Boost Control «A» Circuit High

Code severity and symptoms

The severity of these codes is moderate to severe. In some cases, turbocharger/supercharger problems can cause severe engine damage. It is recommended to fix this code as soon as possible.

Symptoms of a P004E code may include:

• Insufficient boost resulting in reduced engine performance
• Excessive acceleration resulting in detonation and possible engine damage
• Check Engine Light

reasons

Possible reasons for setting this code:

• Faulty boost pressure / turbocharger position sensor
• Defective turbocharger / supercharger
• Defective control solenoid
• Wiring problems
• Defective PCM
• Vacuum leaks if the valve is controlled by vacuum

Diagnostic and repair procedures

Begin by visually inspecting the turbocharger and turbocharger control system. Look for loose connections, damaged wiring, vacuum leaks, etc. Then check the Technical Service Bulletins (TSB) regarding the problem. If nothing is found, you will need to proceed to the step-by-step system diagnostics.

The following is a generalized procedure as the testing of this code differs from vehicle to vehicle. To accurately test the system, you need to refer to the manufacturer's diagnostic flowchart.

Verify system operation by commanding the control solenoid to reposition with a bidirectional scan tool. Raise the engine speed to approximately 1,200 rpm and toggle the solenoid on and off. This should change the engine RPM and the scan tool PID sensor position should also change. If the speed fluctuates, but the PID position / pressure controller does not change, suspect a problem in the sensor or its circuit. If the RPM does not change, suspect the problem is with the control solenoid, turbocharger / supercharger, or wiring.

• To test the circuit: check for power and ground at the solenoid. Note: When performing these tests, the solenoid must be commanded ON with a scan tool. If there is no power or ground connection, you will need to trace the factory wiring diagram to determine the cause.
• Check the turbocharger / supercharger: remove the air intake to check the turbocharger / supercharger for damage or debris. If damage is found, replace the unit.
• Check the position / pressure sensor and circuit: in most cases three wires should be connected to the position sensor: power, ground and signal. Make sure all three are present.
• Test the control solenoid: In some cases, you can test the solenoid by checking its internal resistance with an ohmmeter. See Factory Repair Information for details. You can also connect the solenoid to power and ground to test if it works.

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