What Does P0845 Mean?
The TCM has detected a general malfunction in the transmission fluid pressure sensor/switch "B" circuit. This sensor monitors hydraulic pressure in a secondary clutch pack or servo circuit within the transmission. A malfunction prevents the TCM from accurately managing pressure in that channel, which can affect shift timing and quality.
Common Causes
35%
Faulty transmission fluid pressure sensor/switch B
25%
Damaged wiring in sensor B circuit
20%
Corroded or loose connector at sensor B
15%
Low or contaminated transmission fluid
5%
TCM internal circuit fault
Diagnostic Steps
1
Check the transmission fluid level and condition; address any fluid issues before further diagnosis.
2
Monitor the pressure sensor B PID in live data and compare to factory specifications across different gears and operating conditions.
3
Inspect the sensor B connector for corrosion, damage, or improper seating; this may require transmission pan removal.
4
Measure the sensor resistance and reference voltage at the connector.
5
Check wiring continuity and insulation from the sensor to the TCM.
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
The TCM has detected a general malfunction in the transmission fluid pressure sensor/switch "B" circuit. This sensor monitors hydraulic pressure in a secondary clutch pack or servo circuit within the transmission. A malfunction prevents the TCM from accurately managing pressure in that channel, whic...
The most common cause of P0845 (Transmission Fluid Pressure Sensor/Switch "B" Circuit) is: Faulty transmission fluid pressure sensor/switch B
Typical repair costs for P0845 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The transmission may exhibit harsh or delayed shifts and could enter limp mode. Drivable at reduced performance but avoid heavy loads. Repair promptly to prevent additional transmission wear.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0845 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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