Technical Description of OBD-II Trouble Code
The circuit controlling the bypass of the Exhaust Gas Recirculation Cooler is experiencing low voltage.
What does that mean?
This is a generic diagnostic trouble code (DTC) for the powertrain and is applicable to many OBD-II vehicles (1996-newer). This includes vehicles from various manufacturers such as Ford, Dodge, Ram, Jeep, Chevrolet, Volkswagen, Mercedes, etc. Although it is a generic code, the specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
OBD-II trouble code P245C and related codes P245A, P245B, and P245D are associated with the circuit controlling the bypass of the Exhaust Gas Recirculation (EGR) cooler.
The purpose of the EGR cooler bypass control circuit is to open and close the EGR bypass valve under specific conditions in order to prevent the EGR cooler from becoming overloaded. This prevents fouling, which can negatively impact the performance and efficiency of a diesel engine. The Engine Control Module (ECM) monitors the operation of this circuit by receiving voltage references from the EGR temperature switch and other components. In most configurations, the EGR cooler bypass valve returns the exhaust gases to the intake for combustion. The location of the EGR bypass valve, EGR cooler, temperature switch, and associated components varies depending on the vehicle manufacturer.
When the ECM detects voltage or resistance within the exhaust gas recirculation cooler bypass control circuit that is below the normal range threshold, it sets code P245C and may illuminate the check engine light, service engine soon light, or both.
A typical EGR cooler bypass valve:
What is the severity of this DTC?
The severity of this code can vary from moderate to severe depending on the specific symptoms of the malfunction and the condition of the cooler and bypass valve. A malfunctioning EGR valve or control circuit can cause excessive ignition and pre-ignition, which may result in damage to the pistons, valves, and other internal engine components.
What are some of the symptoms of the code?
Symptoms of a P245C trouble code may include:
What are some of the common causes of the code?
Causes for this P245C code may include:
What are some P245C troubleshooting steps?
The first step in troubleshooting any malfunction is to research the Technical Service Bulletins (TSB’s) specific to the vehicle’s year, model, and power plant. This can save time by providing guidance in the right direction.
The second step is to locate all components associated with the EGR cooler bypass circuit and inspect them for physical damage. Depending on the vehicle, this circuit may include several components such as the temperature switch, bypass valve, EGR valve, EGR cooler, and ECM. Conduct a thorough visual inspection of the associated wiring for any obvious defects such as scraping, rubbing, bare wires, or burn spots. Next, check the connectors and connections for security, corrosion, and damaged pins. This inspection should include all wiring connections to all components, including the EGR temperature switch and the ECM. Consult the vehicle’s specific technical data to verify the configuration of the EGR cooler bypass valve control circuit and confirm the presence of all components, which may include a fuse or a fuse-able link in some applications.
Advanced Steps
The advanced steps are highly specific to the vehicle and require advanced equipment for accurate performance. These procedures involve using a digital multimeter and referencing the specific technical data for the vehicle.
Voltage Checks
The reference voltage and acceptable ranges may vary depending on the vehicle and circuit configuration. The specific technical data will include troubleshooting charts and the appropriate sequence to follow for an accurate diagnosis.
If this process reveals the absence of a power source or ground, continuity testing may be necessary to check the integrity of the wiring, connectors, and other components. Continuity tests should always be performed with the power removed from the circuit, and the normal readings for wiring and connections should be 0 ohms of resistance. Resistance or lack of continuity indicates faulty wiring that is open, shorted, or corroded and must be repaired or replaced.
What are some common repairs for this code?
Common Mistake
We always recommend seeking professional mechanical service to address this issue. However, if that is not possible, we offer the option to permanently delete this specific DTC. All other codes will continue to be addressed. If you are interested in this option, please upload your ECU file to our portal.
