P1818 Pontiac Code - Transmission Fluid Pressure Valve Position Switch-Drive Without 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
- P1818 Pontiac indicates Transmission Fluid Pressure Valve Position Switch-Drive Without 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 P1818 Pontiac 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 P1818 Pontiac?
- 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 P1818 Pontiac?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1818 Pontiac 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.
Need more information about the P1818 Pontiac code?
Need more information on how to fix the P1818 Pontiac code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1818 Pontiac code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P1818 Pontiac Code
1. What does the OBDII code P1818 mean on a Pontiac?
P1818 indicates an issue with the Transmission Fluid Pressure Valve Position Switch, specifically relating to the Drive position without achieving the correct drive ratio.
2. What are the common symptoms of a P1818 code in a Pontiac?
Symptoms may include erratic shifting, the transmission stuck in a single gear, harsh gear engagement, or the illumination of the Check Engine Light.
3. What causes the P1818 code to appear in a Pontiac?
Common causes include a faulty transmission fluid pressure switch, low or contaminated transmission fluid, wiring or connector issues, or internal transmission problems.
4. Can driving with the P1818 code damage my Pontiac's transmission?
Yes, continuing to drive with this code can cause additional stress or damage to the transmission due to improper gear ratios and fluid pressure issues.
5. How can I diagnose the P1818 code on my Pontiac?
Start by checking the transmission fluid level and condition, inspect the pressure switch and related wiring for damage, and use a scan tool to monitor live transmission data.
6. Is the P1818 code specific to Pontiacs?
No, while it can occur in Pontiacs, this code is not exclusive to them and can appear in other vehicles using similar transmission systems.
7. How much does it typically cost to fix a P1818 code on a Pontiac?
Repair costs can range from $100 to $500 or more, depending on whether it’s a simple issue like replacing the switch or a more complex internal transmission repair.
8. Can a bad transmission fluid pressure switch cause the P1818 code?
Yes, a malfunctioning pressure switch is a common cause of the P1818 code as it may not accurately detect or relay fluid pressure conditions.
9. Does resetting the Check Engine Light fix the P1818 code?
No, resetting the light will clear the code temporarily, but the underlying issue must be resolved to prevent the code from returning.
10. Should I replace the transmission fluid to fix the P1818 code?
If the fluid is low or contaminated, replacing it may help. However, if the code persists, further diagnostics are needed to address the root cause.
Discuss the causes and fixes for P1818 Pontiac OBDII Code
Code P1818 Pontiac comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
