Charge Air Control (CAC) Valve

Charge air control (CAC) valve is used to regulate opening of turbo wastegate. Disconnect CAC valve electrical connector. Using DVOM, measure resistance between CAC valve terminals. Resistance should be around 4 ohms between sensor terminals No. 1 and 2, and between terminals No. 2 and 3. If resistance is not as specified, replace CAC valve. If resistance is as specified, go to DTC P1549: CHARGE AIR MALFUNCTION under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 9-3 - TRIONIC T5 article.