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.
Power Supply: Notes
KL30 - Battery Voltage: B+ is the main supply of operating voltage to the ECM.
Power Supplies: The power supplies (KL15 and ECM Relay) are fused to the MS42/MS43 ECM. The fuses are housed in the Engine Fuse Block located in the Electronics Box.
KL15 - Ignition Switch: When the ignition is switched "on" the ECM is informed that the engine is about to be started. KL15 (fused) supplies voltage to the Engine Control Module Relay and the Fuel Injector Relay. Switching KL15 "off" removes the ECM operating voltage.
Engine Control Module Relay: The ECM Relay provides the operating voltage for:
- ECM
- Fuel Injection
- Idle Air Actuator
- Evaporative Emission Valve
- Fuel Pump Relay
- Ignition Coils
- Evaporative Leak Detection Pump
- Camshaft Sensors
- Hot Film Air Mass
- Oxygen Sensor Heaters
Ground: Multiple ground paths are necessary to complete current flow through the ECM. The ECM ground pin numbers are:
- Connector X60001
- Connector X60005
- Pin 4 - Ground for ECM
- Pin 5 - Ground for ECM
- Pin 5 - Ground for ECM
- Pin 6 - Ground for ECM (MS42)
- Pin 6 - Ground for ECM
NO RELATED
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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.