the automatic shutdown relay its located in the power distribution center box under the hood you can try swapping relays with another one temporarily..bosch is one thats borderline lots of people seem to have problems with bosch. i replaced mine with bosch 4 years ago never had a problem still in car when i traded it last month.here is a brief description of how ASD works.think only the sbec part applies to that year ,ngc was controller for later years
The relay is located in the Power Distribution Center (PDC). For the location of the relay within the PDC, refer to the PDC cover for location. Check electrical terminals for corrosion and repair as necessary
The ASD sense circuit (SBEC vehicles) or the engine switched battery (NGC vehicles) informs the PCM when the ASD relay energizes. A 12 volt signal at this input indicates to the PCM that the ASD has been activated. This input is also used to power certain drivers on NGC vehicles.
When energized, the ASD relay on SBEC vehicles supplies battery voltage to the fuel injectors, ignition coils and the heating element in each oxygen sensor.
When energized, the ASD relay on NGC vehicles provides power to operate the injectors, ignition coil, generator field, 02 sensor heaters (both upstream and downstream), evaporative purge solenoid, EGR solenoid (if equipped) wastegate solenoid (if equipped), and NVLD solenoid (if equipped).
For both SBEC and NGC vehicles, the ASD relay also provides a sense circuit to the PCM for diagnostic purposes. If the PCM does not receive 12 volts from this input after grounding the control side of the ASD relay, it sets a Diagnostic Trouble Code (DTC). The PCM energizes the ASD any time there is an engine speed that exceeds a predetermined value (typically about 50 rpm). The ASD relay can also be energized after the engine has been turned off to perform an 02 sensor heater test, if vehicle is equipped with OBD II diagnostics.
As mentioned earlier, the PCM energizes the ASD relay during an 02 sensor heater test. This test is performed only after the engine has been shut off for SBEC vehicles. On NGC vehicles it checks the 02 heater upon vehicle start. The PCM still operates internally to perform several checks, including monitoring the 02 sensor heaters.
Last edited by BillS; 08-25-2012 at 11:11 AM.