P1816 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 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 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?
- 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?
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 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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Information for Specific Makes
- P1816 Buick — Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
- P1816 Cadillac — Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
- P1816 Chevrolet — Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
- P1816 GMC — Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
- P1816 Infiniti — Park/Neutral Position Switch
- P1816 Nissan — Park/Neutral Position Switch
- P1816 Pontiac — Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
- P1816 Saturn — Transmission Fluid Pressure Valve Position Switch-Park/Neutral With Drive Ratio
Frequently Asked Questions about P1816 Code
1. What are common symptoms of OBDII code P1816?
- Common symptoms include harsh shifting, delayed engagement when shifting into gear, and the transmission not shifting at all.
2. What causes OBDII code P1816 to trigger?
- This code is typically triggered by a malfunction in the transmission fluid pressure valve position switch related to the park/neutral with drive ratio.
3. How can I diagnose the issue causing OBDII code P1816?
- A thorough diagnostic scan using an OBDII scanner can help pinpoint the specific issue with the transmission fluid pressure valve position switch.
4. Can driving with OBDII code P1816 cause further damage to the vehicle?
- Continuing to drive with this code may lead to further damage to the transmission system, so it is recommended to address the issue promptly.
5. Is it safe to continue driving the vehicle if OBDII code P1816 is present?
- It is not recommended to drive the vehicle with this code present, as it can cause unpredictable transmission behavior and potential safety hazards.
6. How can I repair OBDII code P1816?
- Repairing this code may involve replacing or repairing the transmission fluid pressure valve position switch associated with the park/neutral with drive ratio.
7. Are there any DIY tips for fixing OBDII code P1816?
- While some simple repairs can be done at home, it is recommended to consult with a professional mechanic for accurate diagnosis and repair of this code.
8. How much does it typically cost to repair OBDII code P1816?
- The cost of repairing this code can vary depending on the extent of the damage and the specific repairs needed, but it may range from a few hundred to over a thousand dollars.
9. Can OBDII code P1816 be a recurring issue?
- If the underlying cause of the code is not properly addressed, it can recur and cause ongoing transmission problems.
10. Will resetting the OBDII code P1816 make it go away permanently?
- Simply resetting the code may temporarily clear the warning light, but the underlying issue causing the code will need to be addressed to prevent it from reoccurring.
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