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 (PCM)
The PCM controls the engine for better fuel economy, emissions control, and failure mode detection and storage.
The PCM is on the standard corporate protocol (SCP) communications network. If one of the bus wires becomes short to ground or voltage, or if some but not all termination resistors are lost, communications can continue. Check circuits (P/LB) and (T/O) between the PCM 0140-175 and the DLC D-01. The total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms there is an open circuit in the SCP communications network, damage to the DLC D-01, damage to the PCM 0140-175, or a problem in the in-line connector.
For additional PCM information, see ELECTRONIC ENGINE CONTROL (EEC) SYSTEM .
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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.