Powertrain Control Module (Pcm)

The PCM on bi-fuel models operates just as it would on gasoline models. When vehicle is operated in GAS mode, PCM monitors engine operating conditions by input received from engine sensors and AFCM. Control of output actuators determines fuel mixture and idle speed. For PCM location, see POWERTRAIN CONTROL MODULE LOCATION  table.

The engine control system consists of the PCM, relays, modules, sensors, switches and actuators. The PCM sends out electrical reference signals to engine sensors and then analyzes the return signals. The engine sensors supply the PCM with specific information, in the form of electrical signals, to determine engine operating conditions.

PCM uses a memory integrated circuit chip which stores information for Keep Alive Memory (KAM). KAM stores memory of vehicle operating conditions and then uses this information for adaptive learning strategy. KAM remains powered with ignition off so that input and output information is not lost.

In the event that one or more input sensors fail, the PCM initiates an alternative strategy called Failure Mode Effects Management (FMEM) to allow the vehicle to maintain driveability. In the event of PCM failure, Hardware Limited Operation Strategy (HLOS) will be activated. HLOS is a system of alternate circuitry that provides minimal engine operation if the PCM fails. During HLOS, all self-test function will stop and system will be controlled by electronic hardware.

Malfunction Indicator Light (MIL) will remain on whenever FMEM or HLOS is in operation. FMEM and HLOS substitute a fixed signal and continue to monitor system failure. If signal(s) return to within operating limits, PCM will resume normal operation.