Neon L4-2.0L DOHC (1996)
Air Bag Control Module: Description and Operation
OPERATION
The ACM/Air Bag System Diagnostic Module (ASDM) contains safing sensor and energy reserve capacitor, while the ACM/Air Bag Electronic
Control Module (AECM) contains impact sensor and energy reserve capacitor. The ACM monitors system to determine system readiness. The
ACM will store sufficient energy to deploy air bag for two minutes after battery has been disconnected. The ACM contains an on board
diagnostics function that will illuminate air bag warning lamp when a system fault occurs.
CIRCUIT OPERATION
Two different circuits supply battery voltage from the fuse block to the Airbag Control Module (ACM), F15 and F25. The F15 and F25 circuits
are connected to separate bus bars internal to the fuse block. Different circuits from the Power Distribution Center (PDC) and ignition switch
supply battery voltage to the fuse block bus bars.
The F25 circuit supplies battery voltage to the ACM only when the ignition switch is in the RUN position. The F15 circuit powers the ACM when
the ignition switch is in either the START or RUN position.
An internal bus bar in the ignition switch connects the A1 circuit from the PDC to the A21 circuit when the switch is either the START or RUN
position. The A21 circuit supplies battery voltage to the bus bar in the fuse block that feeds the F15 circuit. A 30 Amp fuse in the PDC protects
the A1 and A21 circuits. A 10 Amp fuse in the fuse block, cavity 9, protects the F15 circuit.
When the ignition switch is in the RUN position, it connects the A2 circuit from the PDC to the A22 circuit. The A22 circuit supplies battery
voltage to the fuse block bus bar that feeds the F25 circuit. A 40 Amp fuse in the PDC protects the A2 and A22 circuits. A 10 Amp fuse in the
fuse block, cavity 5, protects the F25 circuit.
The ACM has a case ground and an external dedicated ground, circuit Z6. The dedicated ground connects to the instrument panel right center
support.
