Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Powertrain Control Module
Powertrain Control Module (PCM) on bi-fuel models operates just as it would on gasoline models. When vehicle is operated in gasoline mode, PCM monitors engine operating conditions by input received from engine sensors and AFCM. Control of output actuators determines fuel mixture and idle speed. PCM is located on right rear of engine compartment.
The engine control system consists of PCM, relays, modules, sensors, switches and actuators. PCM sends out electrical reference signals to engine sensors and then analyzes input signals. Engine sensors supply 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, PCM initiates an alternate strategy called Failure Mode Effects Management (FMEM) to allow 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 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.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.