abbottdan Report post Posted July 6, 2013 Does anyone know the transmission diagnostic plug location for 2005 Vectra with an Allison 3000MH (Freightliner XC chassis) Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 6, 2013 Read the faults at the keypad. Share this post Link to post Share on other sites
five Report post Posted July 7, 2013 Read the faults at the keypad. Agree, the owner's manual will tell you how to use it. Share this post Link to post Share on other sites
wolfe10 Report post Posted July 7, 2013 Yes, the shift pad can be used for checking oil level and for diagnostic codes. But, the plug must be used for an Allison dealer to do any programming change. Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 7, 2013 I believe the engine port is used for programming the trans. I know they used it to change the speedo output of the trans when I change rearend ratio. Share this post Link to post Share on other sites
richbinkley Report post Posted July 9, 2013 Not sure how familiar you are with Allison so I will answer as if you are new to this. I would start by contacting Winnebago and ask where they located the connector. It is for connecting the Allison diagnostic tool ( Doc program ). You cannot use automotive OBDII tools to read the info. On the trucks I worked on the diagnostic plug was a round plug with 9 pins. There are several types of connectors used for the diagnostic plug. My guess this connector would located in the rear compartment close to where the Allison ECU is located. Anyway it would be good to identify where this connector is so if you need service you can tell a tech where it is. Rich Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 9, 2013 There is usually two locations, one back at the engine and the other near the steering column. Share this post Link to post Share on other sites