Powertrain Controls - ECM/PCM

Chart - Code 46 Vehicle Anti-Theft Fault:

Wiring Diagram for Vehicle Anti-Theft System:

CODE 46 - VEHICLE ANTI-THEFT SYSTEM (VATS) CIRCUIT


Circuit Description:
The Vehicle Anti-Theft System (VATS) is designed to disable vehicle operation if the incorrect key or starting procedure is used. The VATS decoder module sends a signal to the Electronic Control Module (ECM) if the correct key is being used. If the proper signal does not reach the ECM on CKT 963, the ECM will not pulse the injectors "ON" and thus not allow the vehicle to be started. Code 46 will set, if the proper signal is not being received at ECM terminal "B6", when the ignition is turned "ON."


Test Description: Numbers below refer to circled numbers on the diagnostic chart.
1. If the engine cranks, and a Code 46 is stored, it indicates that the portion of the module which generates the signal to the ECM is not operating or the 963 CKT is open or shorted to ground. The ECM may be faulty but a defective VATS decoder module is more likley.



2. If Code 46 is stored, and the engine will not crank, it indicates that there is a VATS problem or an incorrect key or starting procedure is being used.