Welcome to the FMCA Forum.I am not aware of any transmission temperature issue that could cause the engine ECM to shut down the engine.Best advice is to take the coach is to any Caterpillar dealer who can then download the stored fault codes in the ECM-- far better than our speculation.To find the closest Caterpillar dealer: <a href="http://www.cat.com/dealer-locatorClick">http://www.cat.com/dealer-locatorClick</a> on On Highway (since you are not