P045C Exhaust Gas Recirculation B Control Circuit Low

P045C Exhaust Gas Recirculation B Control Circuit Low

You must have encountered this code in your vehicle someday, but is it exactly the P045C engine code?

In simple language, it is basically a Diagnostic Trouble Code (DTC) or a generic powertrain code that is applicable to OBD-II equipped vehicles with an Exhaust Gas Recirculation System.


What is the P045C Engine Code?

The P045C is an error code that refers to a failure in the Exhaust Gas Recirculation system.

To understand this, let me first tell you what is Exhaust Gas Recirculation.

Exhaust Gas Recirculation or EGR is basically a system that is used to reduce the combustion temperature leading to reduced emissions.

Now, if the engine control module detects the EGR is not operating properly as requested, it

will show error code P045C.

There are many vehicles that can show the P045C error including Land Rover, Dodge,

Chrysler, Ford, Toyota, Honda, etc.

The error is repairable but the process is different for different vehicles.

P045C Exhaust Gas Recirculation B Control Circuit Low

Why Does the P045C Error Show?

Let me now explain to you in detail why the P045C error code is showing in your vehicle. As

you know what’s an EGR, but do you know how it works?

To maintain the cylinder head temperature in the vehicle, the engine management computer opens or closes the Exhaust Gas Recirculation as per the speed, load, and temperature.

Let me explain this with an example for better understanding. Suppose, you have a speaker with a volume slider that you can move up and down to adjust its volume.

If the slider works perfectly, the speaker will respond and the sound level will increase or decrease accordingly.

But if you move the slider and there is no change in volume, this means there is an issue with the connection or sensor in the speaker.

This similar happens to the EGR in your vehicle. The vehicle’s computer expects to see a change in voltage as the EGR opens or closes, but if the computer is unable to detect any change in the voltage, it indicates the error P045C.

Causes of P045C EGR Error Code?

The P045C may be due to various causes. The common causes are:

  • Wiring issues such as Short to Ground, which means if your vehicle’s wire is
  • damaged, it causes the wire to come in contact with your vehicle’s metal body or ground, which causes a hindrance in the EGR circuit.

Battery voltage Short issue which may happen if there is an excess current flow that can damage the components.

Loose connectors or damaged Pins connecting various components which may create hindrances.

● There may be a mechanical failure due to which the valve is unable to open or close.

● An issue in the ECU or computer in your vehicle including firmware bugs or any hardware failure.

● A failure in the Solenoid can be a reason for the EGR valve to function properly

● A failure in the Pintle can be a reason for the EGR valve to function properly

P045C Exhaust Gas Recirculation B Control Circuit Low

How to Fix P045C Error in Your Vehicle: Step by Step Guide

If you are facing the issue of P045C in your vehicle then this guide is going to help you a lot.

I have repaired many vehicles showing this code easily and here is how you can do the same.

First thing first, there are a few tools you will need to fix the error code P045C:

● Jumper wire

● OHM Meter

● EGR wiring schematic

● Two paper clips or sewing needles

Now let’s start with the procedure and fix your vehicle.

● Check for the Pintle first. Open the hood, and turn on the engine of your car. If the engine doesn’t run smoothly, the pintle is stuck in the EGR. Replace the EGR.

● Now, check the wire connector on the “B” EGR.

  •  You’ll find 5 wires, two wires which are outside are for battery voltage and ground.
  •  The three wires in the center are potentiometers which are responsible for signaling the amount of EGR flow to the computer.
  •  Check the connector of these wires thoroughly if there are any loose connectors or damaged pins.

● Now, take the OHM meter and check with the terminal of the three-wire in the center with the red lead and the black one to the ground. Turn it on and look for 12 volts and both end terminals.

● If –

  • no voltage is visible on the meter, then the wire is damaged between the EGR and the ignition buss
  •  If it displays 12 volts on one side only, replace the EGR as the EGR has an internal open

Now, take out the connector from the EGR. Turn the key on of the vehicle, do not turn the engine on, check the outer terminals for power.

Check which one is showing 12 volts and change the connector.

● Moving to the next step, put a paper clip in the end terminal that was not showing any power, the ground terminal, and attach the jumper to the paper clip. Put the jumper wire to the ground.

  •  As the EGR energizes, there should be a “Click” sound, now take off the ground wire and start the engine.
  •  Put the wire to the ground, and you’ll see the engine start rough and smooth out as the ground wire is removed.

● If you heard the “Click” sound and if your vehicle’s engine starts rough, this means there is no issue with the EGR, the problem is electrical.

  • If this is not the case, then replace the EGR.

● Next, you can do is, check the center terminals on the EGR connector. As you turn the key on, the OHM meter should show 5 volts if there is no issue with the computer.

● Turn the key off, use the EGR wiring diagram, and find the “EGR Reference Voltage” terminal on the computer.

  • Use a paper clip and place it in the computer connector to back-check the terminals.

● Now turn on your vehicle’s key, if it shows 5 volts is showing, this means the computer is good and the problem is in the harness to the EGR.

  •  If it’s showing no voltage, this means the issue is with the computer.

P045C Exhaust Gas Recirculation B Control Circuit Low

How to Repair EGR Without Replacing the Computer

It’s not that difficult to repair the EGR without replacing the computer but it may take some time if you are new. Here’s how you can do it:

● Check the EGR wiring diagram and search for the coolant temperature voltage reference terminal.

● Turn on the key, take the OHM meter, and check this terminal.

  • If it is showing 5 volts, turn off the key and mark the two reference terminals used in these tests.

● Take off your vehicle’s computer connectors

  •  Take a jumper wire and solder it between the two terminals you have marked before.

● Plug in the connector again

  • The EGR will work normally without replacing the computer.

To Wrap Up

I hope you got your answer to the error code P045C and how can you fix it. I have tried to explain it as much as I can.

If you are unable to fix it yourself, you must check the user manual, if your vehicle is under warranty take it to the service center.

You can also contact a professional mechanic for this.

If you have any other queries, you can ask in the comments below.



1. Is it possible to fix the error P045C in my car?

Yes, it is possible to fix the error P045C of your car. It may be a bit difficult at first if

you are not a technical guy, you can contact a professional mechanic as well.

2. Are there specific tools required to fix the P045C error in my car?

Yes, there are a few tools that are necessary including an OHM meter or volt meter,

jumper wire, EGR wiring diagram, and two paper clips or pins.

3. Is there any risk if I drive with the engine code P045C?

There is no such risk if you drive with the error code P045C in your vehicle and still

you must fix it.

4. How much would it cost to fix the code P045C in my car?

It may cost between $75 and $150, depending on the labor charges in your area.

5. What can be the symptoms of error P045C in my car?

There can be a few symptoms like a drop in fuel economy, rough engine running,

decrease in power of your vehicle, difficulty to start the engine, etc.

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