ENGINE SCAN DIAGNOSIS Is your check engine light on? Includes:  Scan powertrain control module  Perform all necessary testing to diagnose trouble codes With This Coupon: FREE! Excludes the dismantling of engine, transmission or differential. Does not include repairs which may be required after inspection. Any necessary repairs can be completed in our Service Department. GM vehicles only and valid only at Courtesy Chevrolet. See service advisor for details. Present this coupon at time of write up. Op code PSD Call us at 602-714-3120 or stop by for Details!