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.
Diagnostic Trouble Code (DTC) Information
2004 Volvo V70 L5-2.4L VIN 64 B5244S6SECTION Diagnostic Trouble Code (DTC) Information
Diagnostic trouble code (DTC) information ECM-301A
Condition
The engine control module (ECM) checks the signals from the camshaft position (CMP) sensor on the exhaust side.
When the engine speed (RPM) exceeds 500 rpm the control module assumes that the camshaft position (CMP) sensor will make 5 flank changes during each crankshaft revolution. Faults can be counted 19 times within 200 engine rotation intervals before the engine control module (ECM) interprets this as a fault and stores ECM-301A.
Diagnostic trouble code (DTC) ECM-301A can be diagnosed when the engine is running.
Substitute value
- The transmission input speed sensor is used if it is working.
Possible source
- Contact resistance
- Incorrectly adjusted camshafts
- Short-circuit to supply voltage in the signal cable
- Defective camshaft position (CMP) sensor on the exhaust side.
Fault symptom[s]
- Engine difficult to start
- The engine misfires.
RENDER: 1.0x
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.