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P1820 GMC Code - Internal Mode Switch Circuit 'A' Low

- Code Popularity: 1,925 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P1820 GMC?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Internal Mode Switch
  • Internal Mode Switch harness is open or shorted
  • Internal Mode Switch circuit poor electrical connection
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How to Fix the DTC P1820 GMC?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1820 GMC code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

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

Code P1820 GMC Description

With the engine runtime over 5 seconds, system voltage from 8-18v, Fuel Cutoff inactive, engine torque from 30-148 ft-lb (40-200 Nm), the Powertrain Control Module (PCM) detects that the Internal Mode Switch (IMS) signal indicated PARK for 2 seconds and then the IMS indicated a transitional state between D4 and D3, conditions met for 5 seconds.

OBDII Code P1820 GMC - Internal Mode Switch Circuit 'A' Low - AutoCodes.com
P1820 GMC Code - Internal Mode Switch Circuit 'A' Low

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Code P1820 GMC comments

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