As title says, the EBP stays at 43psi key on running or not. MAP is at 13.7psi like it should be. tried a new sensor and also unplugged and no diff. Wiggled engine wiring harness and it never dropped. No tuner. Codes are P0472 and P0475. Truck runs very sluggish. 4.7v on EBP plug

 

I would check the wiring harness and look for any damage. It should definitely not be showing that value when the sensor is unplugged.

Maybe get a multi-meter and check continuity in the length of wire from the PCM connector to the end of the plug.

If all is well there, it may be some issue in the PCM.

 

It sounds like he is measuring 4.7V on the plug when it is unplugged key on which is normal vref isn't it? The part of the equation we are missing is what the voltage is back to the PCM when plugged back in. Unless I am missing something?

edit: Ok you must mean the 43 PSI value

 

The EBP Sensor and EPV work in unison to warm the Engine Faster to OT. It is PCM but not to the extent that it "hurts" fuel mileage. There is additional fuel delivered to maintain an increased idle while active. However, when the Tube is blocked, it does not allow the pressure transducer to fluctuate by the exhaust pressure. All this is controlled based on following parameters:

IAT (Intake Air Temperature) below 10°C (50°F) to activate EBP

EOT (Engine Oil Temperature) below 70°C (15B°F) to activate EBP

A high pitched whine, in exhaust system, will be heard when EBP device is active.

At the turbo exhaust outlet is a butterfly that when actuated will restrict the exhaust flow, this causes the engine to work harder in cold ambient and generate engine coolant temperature quicker for cab heat.

The actuation of this device is controlled by the PCM and the EBP regulator located in the turbo pedestal. The EBP regulator restricts lube oil flow out of the turbo (center housing) and directs oil to the turbo pedestal which pushes the EBP actuator arm outward causing the butterfly to close or restrict exhaust flow.

The PCM uses the EBP sensor to monitor the exhaust restriction. The EBP sensor is connected to the right exhaust manifold using a pipe and fitting.

The exhaust back pressure device will open when the accelerator pedal is depressed and the exhaust back pressure increases. When the exhaust back pressure decreases or the vehicle is in a steady state, exhaust back pressure decreases per the EBP sensor, the EBP regulator can, and will activate the EBP device again even while going down the highway as long as the EOT temperature is below the specifications. Vehicle in Park (A/T) Neutral and Park Brake Set (M/T) the Engine Idle will increase as well to maintain engine running and not stalling. On M/T models the ECT will determine Idle Speed.

EPR: Exhaust Back Pressure Regulator, also EBP regulator Output: For quicker engine warm-up at cold temperatures. If the IAT is below 37°F (50°F some models) and the EOT is below 140°F (168° some models) the PCM sends a duty cycle signal to a solenoid which controls oil flow from the turbo pedestal. This causes a servo to close a valve at the turbo exhaust outlet. The PCM monitors the EBP input to determine if the EPR needs to be disabled to provide power for increased load, then reapplies the EPR as load demand decreases until EOT or IAT rises.

The Exhaust Back-Pressure sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a linear analog voltage signal that indicates pressure. The Exhaust Back-Pressure sensor measures the pressure in the RH exhaust manifold. This sensor is used in conjunction with the exhaust back-pressure regulator to form a closed loop exhaust back-pressure control system.

An open or short in the Exhaust Back-Pressure sensor wiring will result in a low out of range voltage at the PCM, and the PCM will disable Exhaust Back-Pressure control.

Measurements are determined by both PSI and RefVdc KOEO and KOER. Disconnecting the EBP at the Turbo Base should disable the valve and it should be open up to 99%. A Hole In the EBP Tube will send erroneous signals as well.

 

A dead short from signal to Vref will read about 53-54 PSI EBP. A dead short from signal to ground will read 0 PSI EBP - this is neither. What is being used to read the EBP?

 

Was using AE to read EBP. It was reading 43psi plugged or unplugged. And yes I was reading the volt numbers on the wire with it unplugged. I was looking on another forum and there they suggested that if sensor is unplugged the PCM will default to 43psi.. Does that make sense? Anyway, because of that theory, I tried a third EBP sensor and now it's all reading fine.. around the 13-15psi at idle. Thanks a lot everyone for your replies. Appreciate it.