sgort2

I'm hoping to find a member or shop that has a Star Diagnostic tool, iCarsoft MBII or Autel MD802 Elite tool to diagnose a red battery light on a 2005 SL 500, with 119K miles. My car went into limp mode, (1st gear only), with the following CELs: ABS, ESP, and red battery. I pulled the car over and shut the car off. I tried to re-start the car and only got a click from the starter. I had the car towed to my house and started checking voltages. With the car off the accessory battery reads 12.39V, starter battery reads 12.9V. I'm able to start the car with a battery booster, with the car running the accessory battery reads 14.06V, starter battery reads 14.4V. Putting the car into D or R results in a hard clunk but each gear seems to engage without any other issues. I initially thought brushes or alternator but with 14+V at each battery while running I'm at a loss, any help is greatly appreciated.