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.
2009 Chrysler 300 V6-2.7LFACTORY OEM SERVICE PROCEDURE
Power Grounds
POWER GROUNDS
The Powertrain Control Module (PCM) has 2 main grounds - power grounds for engine functions and power grounds for transmission functions (if equipped with 42RLE). Both of these grounds are referred to as power grounds. All of the high current electrically noisy devices are connected to these grounds. The sensor return comes into the sensor return circuit internal to the module, passes through noise suppression, and is then connected to the power ground internal to the module so as to minimize the effects of the high current and electrically noisy devices on various sensor signals.
The power ground is used to control ground circuits for the following PCM loads:
- Fuel injectors
- Ignition coil(s)
- Certain relays/solenoids
- Certain sensors
Factory Service Tools
Use the Manual With the Right Hardware
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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.