P18C2 - Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3   
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P18C2 Possible Causes

  • Faulty Internal Mode Switch
  • Internal Mode Switch harness is open or shorted
  • Internal Mode Switch circuit poor electrical connection

First diagnose P18C2 code

    Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded terminals.

Cost of diagnosing the P18C2 code

    Labor: 1.0

    The cost of diagnosing the P18C2 code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

P18C2 Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P18c2 Description

The internal mode switch indicates to the Transmission Control Module (TCM) which gear position the vehicle operator has selected. The internal mode switch consists of 5 separate hall effect switches. Each hall effect switch is supplied a 9 V reference circuit and a signal circuit from the TCM. Each signal circuit for each gear selector position will have either a voltage reading of 0.70-0.96 V indicting On or 1.68-2.38 V indicating Off. The voltage values on each internal mode switch circuit will change and are dependent on the position of the gear selector. The state of each internal mode switch A/B/C/P/S signal circuit is displayed on the scan tool.
OBDII Code P18c2 - Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range - AutoCodes.com

P18C2 More Information

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P18C2 Information for specific makes

  • P18C2 BUICK Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range
  • P18C2 CADILLAC Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range
  • P18C2 CHEVROLET Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range
  • P18C2 GMC Internal Mode Switch 'P' Circuit Stuck On Invalid Voltage Range

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