Circuit Description

PCM and Throttle Actuator Control (TAC) module communicate through a dedicated serial data circuit. This diagnostic monitors accuracy of serial data transmission between PCM and TAC module. If a loss of data or invalid data is detected, this DTC will set.

DTC will set when following conditions are present:

• Ignition switch in CRANK or RUN position.
• Ignition voltage greater than 8.5 volts.
• Invalid or missing serial data messages are detected for a predetermined amount of time.
• Conditions met for less than one second.