P1816 Cadillac Code - Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
Quick Answer
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. Common causes include 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. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1816 Cadillac indicates Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio.
- Common causes
- Common causes include 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.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1816 Cadillac Description
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.
What are the Possible Causes of the DTC P1816 Cadillac?
- 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
How to Fix the DTC P1816 Cadillac?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1816 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P1816 Cadillac Code
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