Diagnostic Trouble Code (DTC) Information

2003 Volvo V70 2.4 L5-2.4L VIN 61 B5244SSECTION Diagnostic Trouble Code (DTC) Information





Diagnostic trouble code (DTC) information ECM-4201

Condition
After start-up, the engine control module (ECM) checks the efficiency of the catalytic converter by switching between rich and lean fuel/air mixtures. When the change-over is made, the signal from the rear heated oxygen sensor (HO2S) is checked and the time taken for the probe to switch. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the rear heated oxygen sensor (HO2S) switches too quickly.

Substitute value
- None.

Possible source
- Air leakage in the exhaust system
- One or more damaged injectors.
- Damaged catalytic converter.

Fault symptom[s]
- Malfunction indicator lamp (MIL) lit.

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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.