Error code

OBD2 P2018

OBD2P2018
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Intake Manifold Runner Position Sensor/Switch Circuit Intermittent.

Severity

moderateCan drive but performance issues may occur.

Summary

P2018 indicates an intermittent circuit issue with the intake manifold runner position sensor/switch on bank 1. This can affect engine performance due to improper air flow control.

Symptoms

  • Stored trouble code and illuminated warning light
  • Rough or fluctuating idle
  • Hesitation or surging at certain engine speeds
  • Power loss at some throttle settings

Common Causes

  • Damaged, burnt, shorted, disconnected, or corroded wiring and connectors
  • Defective position switch/sensor
  • Split, hardened, cracked, or dislodged vacuum lines (if applicable)
  • Carbon deposits on control flaps preventing free movement

Diagnosis

  1. Record all fault codes and freeze frame data.
  2. Locate and identify the position sensor/switch, associated wiring, and vacuum lines (if applicable).
  3. Test resistance of the sensor using a digital multimeter and compare with manufacturer specifications.
  4. If necessary, test the operation of the sensor by monitoring signal voltage changes as control flaps are manually opened.

Fixes

  • Replace defective position switch/sensor if resistance or signal voltage readings deviate significantly from specified values.

FAQ

What should I do if the code returns after replacing the sensor?

Reconnect wiring and test for any issues with vacuum lines, carbon deposits on control flaps, or other related components.

Can this issue be caused by a faulty PCM?

A failed PCM is rare but possible. Check all other potential causes before considering the PCM as the fault source.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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