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Q: Transmission acting up and Check Engine and AT light coming on.

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When I put the car in reverse it makes a clunking noise and the car jolts, and the AT light comes on. In addition, the automatic transmission does not go past 3rd gear. The Check Engine light is also on.

If the car makes a clunking sound associated with a jolt, the most likely cause for that would be a transmission or engine mount. Enlist the help of a YourMechanic technician to check these mounts. The technician will likely have you make gear changes inside the vehicle while watching the mounts to check for any play in the mount causing the engine and transmission assembly to jolt to a spot it isn’t supposed to go. As for the two warning lights I would recommend having the technician check your vehicle for trouble codes with an OBD2 scanner. Once the trouble codes are pulled the diagnosis will be more accurate.

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