Transmission Fluid Pressure Sensor/Switch B Circuit
What does P0845 mean?
The P0845 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Sensor/Switch B Circuit. This is a moderate severity code.
Common Symptoms
- Check Engine Light illuminated
- Erratic shifting patterns
- Transmission slipping in certain gears
- Vehicle may enter limp mode
Probable Causes (Ranked by Likelihood)
- Faulty transmission fluid pressure sensor B Very High
- Wiring fault in pressure sensor B circuit High
- Corroded connector at pressure sensor B Moderate
- Internal valve body issue affecting B circuit pressure Low
Step-by-Step Diagnostic Procedure
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Check transmission fluid level and condition
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Monitor pressure sensor B data on a scan tool and compare to sensor A
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Inspect wiring and connector at pressure sensor B for damage
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Test sensor B resistance and compare to manufacturer specifications
Frequently Asked Questions
What is pressure sensor B vs sensor A?
Transmissions with multiple pressure sensors use A and B to monitor pressure at different points in the hydraulic circuit. Sensor B typically monitors a secondary pressure circuit or specific clutch pack pressure.
Can I drive with P0845?
You can drive short distances, but the transmission may not shift correctly. Prolonged driving can cause additional wear to internal components.
Are pressure sensors A and B interchangeable?
In some vehicles the sensors are the same part number, but they are located in different positions. Always verify the correct part number for each location.