What it means
Same as P245A with the control line shorted to ground. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 1 EGR cooler bypass valve routes recirculated exhaust around the cooler when commanded. The control module monitors its electrical control signal and sets P245C when that signal is below the expected range, commonly from a short to ground or a damaged, high-resistance connection.
Common causes
Most likely first.
- Control line shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
How to diagnose it
- Record freeze-frame data and scan for other bank 1 bypass-valve codes to see whether the low signal occurs with a broader power or ground fault.
- Inspect the bank 1 bypass-valve connector for corrosion, moisture, bent pins, and damaged insulation.
- Follow the control wire for the bank 1 valve and check for chafing or a short to ground, especially near brackets and hot exhaust components.
- Measure the control-circuit signal and check its continuity and isolation from ground against the manufacturer's specification.
- If the harness and connector pass, test the bank 1 actuator and module output using the manufacturer's procedure.
Common fixes
- Clean and secure corroded or loose terminals at the bank 1 bypass-valve connector.
- Repair wiring shorted to ground or damaged by chafing.
- Replace a failed bank 1 bypass actuator if the circuit tests correctly.
- Repair a confirmed control-module output fault.
Can I keep driving?
If the engine runs normally, gentle driving may be possible, but avoid heavy load if knocking or power loss occurs. The bank 1 bypass valve may not operate correctly, affecting emissions and engine response.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.