Engine No Start, DTC P0633 Set (Reprogram ECU)

Customers may comment of a no start situation. Technicians may find a DTC P0633 (Immobiliser function not programmed) set in the engine ECU. This code may not clear with Tech 2®.

If a TDM link is attempted, the following message may appear: "ECM is already linked".

This condition may be caused when the Theft Deterrent Module (TDM) fails to correctly read the transponder key. If repeated attempts are made to start the vehicle while in this state, then the tamper mode may become active.

After verifying that the vehicle has the condition described above, perform SPS programming of the TDM from TIS CD 2007/05 or later. Refer to Service Information for the SPS programming procedure.

For vehicles repaired under warranty, use: