Transmission Fluid Pressure Sensor/Switch F Circuit High
The P2826 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Sensor/Switch F Circuit High. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $600 (parts and labor)
Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.
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Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.
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Common Symptoms
- F circuit showing lower-than-actual pressure
- TCM increasing commanded pressure excessively
- Harsh shifts from over-pressure
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Sensor F shorted to reference voltage Very High
- Open ground for sensor F High
- Sensor F reading stuck high Moderate
- TCM input shorted high Low
Step-by-Step Diagnostic Procedure
-
Check sensor F for constant high reading
-
Test sensor F ground circuit
-
Compare reading to actual gauge pressure
-
Verify TCM input circuit
Frequently Asked Questions
Why does a high sensor reading cause harsh shifts?
The TCM thinks pressure is too low and commands more pressure to compensate. Since actual pressure was already correct, the result is over-pressure and harsh shifts.
Can an open ground wire cause P2826?
Yes. Without a ground reference, the sensor signal floats toward the reference voltage, giving a constant high reading regardless of actual pressure.
How do I check the sensor ground?
Measure resistance from the sensor ground pin to the TCM ground. It should be less than 1 ohm. High resistance indicates a poor ground connection.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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