P24C5: EGR Cooler Bypass Position Sensor Exceeded Learning Limit Bank 2

What it means

The bypass valve position sensor learning has reached its software-side limit on bank 2 - typically heavy soot deposits have shifted the mechanical zero beyond the design adaptation range.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The EGR cooler bypass valve directs exhaust gas around or through the cooler, and its position sensor reports how far the valve has moved. The control module learns the valve’s normal closed or reference position; this code sets when that learned position for bank 2 reaches the software adaptation limit, often because soot or binding has shifted the valve’s mechanical reference.

Common causes

Most likely first.

1. Carbon or soot restricting the bypass valve
2. Bypass valve sticking or binding
3. Position sensor or wiring fault
4. Mechanical wear in the valve or linkage

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

1. Check scan-tool freeze-frame data and EGR-related live data to see when the bank 2 bypass position stopped matching the commanded position.
2. Inspect the bank 2 bypass valve, linkage, and nearby wiring for heavy soot, heat damage, loose connections, or visible binding.
3. With the engine off and cool, check whether the bank 2 valve or linkage moves freely using the vehicle’s approved service procedure.
4. Compare commanded and reported bypass position during an appropriate scan-tool actuator test to distinguish sticking from a sensor signal that does not track movement.
5. Test the bank 2 position-sensor wiring and connector, then assess valve wear and perform the manufacturer’s relearn procedure only after correcting any mechanical or electrical fault.

Common fixes

• Repair a loose, damaged, or corroded bank 2 bypass sensor connector or wiring.
• Clean soot from the bank 2 bypass valve and linkage if the manufacturer’s service procedure permits it.
• Repair or replace a sticking or worn bank 2 bypass valve or linkage.
• Replace a faulty bank 2 position sensor and perform the required relearn.

Can I keep driving?

You may be able to drive gently if the engine runs normally, but avoid heavy loads because the bypass fault can contribute to knocking, hesitation, and excess NOx emissions. Stop if knocking becomes severe or power drops sharply, and arrange repair soon.