The transmission fluid pressure manual valve position switch/TFP manual valve position switch uses fluid pressure from the manual valve to tell what gear has been selected. If the ECU sees that a drive ratio is been selected, but the TFP manual valve position switch thinks that reverse and has been selected, a P1817 diagnostic trouble code will be stored.
What Transmission Do I Have?
How Serious is the Code?
In order to compensate for the error, the ECU/TCM will command maximum line pressure inside the transmission. This can cause severe damage to the internal components.
Symptoms
Symptoms of a P1817 DTC include:
- Unusually harsh shifts
- Check engine light
- Limp Mode
Causes
- Failed transmission fluid pressure manual valve position switch/TFP switch
- Short in the TFP valve position switch wiring harness
- Poor connection in the TFP valve positions switch circuit
How to Diagnose the Code?
To determine the cause of a P1817 DTC, electrical test will need to be performed on the transmission fluid pressure manual valve position switch.
What Repairs Will Fix P1817?
Repair any electrical shorts in the transmission fluid pressure manual valve position sensor circuit
Replace the TFP sensor
What Transmission Do I Have?
Related Codes
P1810 – Transmission Fluid Pressure Manual Valve Position Switch
P1816 – Transmission Fluid Pressure Manual Valve Position Switch Park/Neutral with Drive ratio
P1818 – Transmission Fluid Pressure Manual Valve Position Switch indicates Drive without Drive ratio
