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 Description: Notes
The powertrain control module (PCM) is a precision microprocessor that is an essential part of the electronic control system. The PCM is responsible for engine and automatic transmission operation. The PCM is located in the engine compartment. The PCM communicates with other vehicle control modules using the controlled area network (CAN) communication protocol. Outside communication with the PCM is through the data link connector (DLC) located below the left side of the instrument panel (IP).
The PCM performs the OBD II diagnostic tests of the emission related systems. The PCM supplies a buffered voltage, called reference voltage, to the various information sensors and switches. The PCM controls most components with an electronic switch that completes a ground circuit when turned ON. The electronic switch is commonly referred to as an output driver. The PCM is also responsible for a self-diagnosis function and a fail-safe function.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.