Ranger 4WD V6-3.0L VIN V Flex Fuel (1999)
communication network, the NGS Tester must ask for all information; the modules cannot initiate communications.
The SCP communication network will remain operational even with the severing of one of the bus wires. Communications will also continue if one of the
bus wires is shorted to ground or battery positive voltage (B+) or if some, but not all, termination resistors are lost.
Unlike the SCP communication network, the ISO 9141 communication network will not function if the wire is shorted to chassis ground or battery
positive voltage (B+). Also, if one of the modules on the ISO 9141 network loses power or shorts internally, communications to that module will fail.
The Powertrain Control Module (PCM) is on the SCP communication network. The PCM controls the engine for better fuel economy, emissions
control, and failure mode detection and storage.
The Restraint Control Module (RCM) is on the ISO 9141 network. The RCM controls the deployment of the air bags based on sensor input.
The Generic Electronic Module (GEM) and the Central Timer Module (CTM) are on the ISO 9141 network. Only one GEM or one CTM will be on a
vehicle. The CTM will show up as a GEM on the NGS Tester. The GEM is equipped on vehicles with 4-wheel drive or vehicles with power windows.
The CTM is equipped on vehicles with 2-wheel drive and vehicles without power windows. The GEM controls additional functions that include:
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Speed dependent windshield wipers.
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4-wheel shift on the fly
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One touch down power window.
The Remote Anti-theft Personality (RAP) module is on the ISO 9141 communication network. The RAP module controls keyless entry for the vehicle.
The 4-wheel anti-lock brake control module is on the ISO 9141 communication network. The 4-wheel anti-lock brake control module controls the brake
pressure to the four wheels to keep the vehicle under control while braking.
The Passive Anti-Theft System (PATS) module is on the SCP communication network. The PATS module will disable the starting system of the vehicle
and not allow it to start without the correct PATS key.
