OBD
C0018
Left Rear Inlet Control
What it means
C0018 means Left Rear Inlet Control.
Check these first
- The left rear inlet control valve has failed
- An open or short in the left rear inlet control circuit
- Corrosion at the left rear inlet connector
- The ABS module is not driving the left rear inlet valve
What to do next
- Read left rear inlet valve data with a scan tool
- Inspect the left rear inlet connector for corrosion
- Test the inlet control circuit for opens and shorts
- Check the left rear wheel speed sensor signal
- Replace the left rear inlet valve or ABS unit if faulty
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.