INTERNAL EMM FUNCTIONS
Start Assist Circuit (SAC)
When the ignition key is ON, the EMM Start Assist Circuit (SAC) boosts battery voltage (12 V) to 30 V on the system (55 V) circuit.
ROM Verification
The EMM performs a self-test of programming every time it is turned ON. Service code 15 indicates a programming (software) issue. Repro gram the EMM with the correct software program to correct the problem.
Idle Controller
The idle controller reacts to engine operating conditions. Fuel and ignition timings are altered to maintain a specific RPM when engine is cold or warm. The controller is inactive when TPS is advanced from idle position.
RPM Limiter
This feature of EMM programming prevents engine damage due to excessive RPM. At 6250
RPM, fuel and ignition to the cylinders is shut off. Normal engine operation resumes when engine RPM returns to the specified range.
Shift Interrupt
The shift interrupt function of EMM programming shuts off fuel and spark to three cylinders for approximately one second to reduce drivetrain loads and ease shifting, then immediately restores normal engine operation. The shift interrupt switch must be released to its normal open position before the shift interrupt function can be activated again. This function is not operational above 2500 RPM.
The EMM provides voltage to the shift interrupt switch circuit. If the switch or circuit fails, the EMM stores a service code.
Engine Monitor and Warning Systems
Refer to ENGINE MONITORING SYSTEM on p. 99.
Refer to S.A.F.E. WARNING SYSTEM on p. 100. Refer to SHUTDOWN MODE on p. 100.
Fault Code Creation and Storage
Refer to the EMM Service Code Chart at the back of this manual for a complete list of all engine fault codes.
