What does it mean?
This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles with an exhaust gas recirculation system. Vehicle makes may include (but are not limited to) Land Rover, GMC, Chevrolet, Dodge, Chrysler, Ford, Toyota, Honda, etc. Although generic, specific repair steps may vary by make/model.
The exhaust gas recirculation (EGR) system is controlled by a vacuum solenoid. The solenoid is supplied with ignition voltage. The powertrain control module (PCM) controls the vacuum solenoid by grounding the control circuit (ground) or driver.
The main function of the driver is to provide ground to the controlled component. Each driver has a fault circuit that the PCM monitors. When the PCM powers a component, the control circuit voltage is low or near zero. When the component is off, the voltage on the control circuit is high or near battery voltage. The PCM monitors these conditions and if it does not see the appropriate voltage at the right time, this code is set.
The EGR system is used on engines to reduce combustion temperature, which in turn reduces emissions. Refer to a vehicle-specific repair manual to determine what the EGR circuit “B” is in your particular case.
Potential Symptoms
Usually, a fault in the control circuit will leave no noticeable symptoms other than the malfunction indicator lamp (MIL) illuminating. However, if the EGR control solenoid is stuck due to debris, etc., the code may be accompanied by misfires during acceleration, rough idle, or a stalling engine.
Causes
of an EGR P045A code may include:
Faulty EGR solenoid
Excessive resistance in the control circuit (PCM controlled ground) due to an open, chafing, or damage to the harness
Poor connection to the EGR solenoid harness (worn or loose pins)
Water intrusion at the EGR solenoid harness
Blockage in the EGR control solenoid holding or closing the solenoid causing excessive resistance
Loss of EGR solenoid supply voltage
Faulty PCM
Possible Solutions
If you encounter this fault code, we encourage you to refer to a vehicle-specific repair guide for your particular year, make, model, and engine. The following information is more general in nature. Also, be sure to check for TSBs (technical service bulletins) that may apply to your vehicle.
With the ignition on and engine off, use a scan tool to activate the EGR solenoid. Listen or feel for a click, indicating the solenoid is operating.
If the solenoid operates, you will need to check the current draw on the ground circuit. It should be less than one amp. If it is, the problem is intermittent. If not, there is excessive resistance in the circuit and perform the following:
1. When activated, see if you can blow lightly through it. If you cannot, there may be a blockage causing excessive resistance. Replace the EGR solenoid as needed. If there is no blockage, disconnect the EGR solenoid and the PCM connector containing the EGR solenoid control circuit. Using a digital volt-ohmmeter (DVOM), check the resistance between the control circuit and battery ground. This should be infinite. If not, there is a short to ground in the control circuit. Repair the short to ground and retest as needed.
2. If the solenoid does not click as it should, disconnect the EGR solenoid connector and connect a test light between the two wires. Using the scan tool, activate the EGR solenoid. The light should come on. If it does, replace the EGR solenoid. If it does not, perform the following: a. Check for 12 volts on the solenoid ignition supply voltage. If not present, inspect the supply circuit for an open or short due to chafing or breakage and retest. b. If it still does not work: manually ground the EGR solenoid control circuit. The light should come on. If it does, repair the open EGR solenoid control circuit and retest. If not, replace the EGR solenoid.