Chevrolet P1818: Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Drive without Drive Ratio
Is your scanner showing Chevrolet P1818?
No worries. We'll show you what it means and how to deal with it.
Chevrolet P1818: Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Drive without Drive Ratio
OVERVIEWWhat Does The Chevrolet P1818 Code Mean?
Some customers may comment on the illumination of the Malfunction Indicator Lamp (MIL) or the Service Engine Soon (SES) light, the power door locks, cruise control, shift interlock, retractable hardtop being inoperative and engine speed revs limited to 4,000 RPM in first gear after a cold start or cold soak with temperatures between 0° to 10°C (32°F to 50°F).
Customers with hybrid vehicles may also comment on the following conditions:
— Hybrid Autostop, regen or boost inoperative
What Are The Potential Causes Of The Chevrolet P1818 Code?
These conditions may be caused by the TCM setting a false DTC P1818 (Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Drive without Drive Ratio).
How Can You Fix The Chevrolet P1818 Code?
Verify the conditions and reprogram the transmission control module (TCM) with the new
updated calibration using the procedure below.
- Check for DTCs.
- Clear DTC P1818.
- Start the engine.
- Apply the brake pedal.
- Place the transmission in reverse.
- With a Tech 2®, monitor the transmission fluid pressure (TFP) switch parameter.
- If the TFP parameter indicates Reverse, reprogram the TCM with the updated
calibration. - If the TFP parameter indicates Park/Neutral, refer to DTC P1818 in SI for further
diagnosis
Important: Confirm the newest calibration includes the “false P1818 fix”.
An updated TCM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern. Reprogram the TCM with the software now available in the TIS2WEB using the Service Programming System (SPS).
Clear any codes and verify the condition has been fixed.
Recommended Parts
Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:
>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> ACDelco 29546972 GM Original Equipment Automatic Transmission Fluid Pressure Switch
Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!
Reference Sources
GM, 2013, Service Bullettin – Prior To Any Circuit Testing.
