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P1816 GMC Code - Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio

- Code Popularity: 2,666 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P1816 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 Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch
  • TFP Valve Position Switch harness is open or shorted
  • TFP Valve Position Switch circuit poor electrical connection
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How to Fix the DTC P1816 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 P1816 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 P1816 GMC Description

The automatic Transmission Fluid Pressure (TFP) manual valve position switch consists of five pressure switches (two normally-closed and three normally-open) and a Transmission Fluid Temperature (TFT) sensor combined into one unit. The combined unit mounts on the valve body.
The Powertrain Control Module (PCM) supplies ignition voltage for each range signal. By grounding one or more of the circuits through various combinations of the pressure switches, the PCM detects which manual valve position you select. The PCM compares the actual voltage combination of the switches to a TFP manual valve position switch combination table stored in memory.
The TFP manual valve position switch cannot distinguish between PARK and NEUTRAL because the monitored valve body pressures are identical. With the engine OFF and the ignition switch in the RUN position, the TFP manual valve position switch indicates PARK or NEUTRAL. Disconnecting the AT inline 20-way connector removes the ground potential for the three range signals to the PCM. In this case, with the engine OFF, and the ignition switch in the RUN position, D2 will be indicated.

OBDII Code P1816 GMC - Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio - AutoCodes.com
P1816 GMC Code - Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio

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