P024A: Charge Air Cooler Bypass Control A Range/Performance

The charge air cooler bypass is a flap or valve that routes compressed air around the charge air cooler, so the engine and exhaust warm up faster after a cold start; when warm it closes or opens partly to control intake air temperature. It is driven by an electric motor with a built-in position sensor or by a solenoid and vacuum can. P024A is the functional fault: the bypass does not follow its command, judged from the position sensor or from the expected temperature effect – Bosch describes comparing the cooler's efficiency with the valve closed and open, using modelled air temperature before and measured temperature after the cooler. FCA documents P024A, together with P026E, on the 2017 Alfa Romeo Giulia and 2018 Stelvio with the 2.0 turbo and fixed it with an engine software update, so check the software level first.

Symptoms

• Check engine light on
• Longer warm-up or higher charge air temperature
• Possibly less power from boost limitation

Most likely causes

• Bypass flap sticking, coked or oily (oil from crankcase ventilation or turbo)
• Actuator weak or vacuum line leaking
• Engine software (FCA 2.0 turbo)
• Position sensor inaccurate or connector corroded

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the hoses, clamps, and intercooler
2. Compare the reading with other engine data while varying the engine speed.
3. Compare commanded and actual pressure in live data
4. Check the actuator's movement
5. Check the vacuum hoses and the solenoid valve
6. Check the oil and the turbo shaft play before replacing it

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P024A means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 2: Fuel injection
• 4A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P024A?

Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.

What causes code P024A?

The most common causes are: bypass flap sticking, coked or oily (oil from crankcase ventilation or turbo); actuator weak or vacuum line leaking; engine software (FCA 2.0 turbo).

Related codes

• P024BCharge Air Cooler Bypass Control A Stuck
• P024DCharge Air Cooler Bypass Position Sensor A Circuit Range/Performance
• P022ACharge Air Cooler Bypass Control A Circuit/Open
• P026ACharge Air Cooler Efficiency Below Threshold
• P0299Turbocharger/Supercharger A Underboost Condition

Sources

• law.cornell.edu: 13 CCR 1968.2
• patents.google.com: US8417484
• static.nhtsa.gov: MC 10216318 9999
• static.nhtsa.gov: MC 10175165 9999

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.