A transmission band is a friction lined metal strap that squeezes around a spinning clutch drum to stop it from spinning so a gear change can occur. The transmission band is activated by the brake band apply solenoid, which is a little electromechanical device that is used to route pressurized transmission fluid. If a low voltage condition is detected (usually because of an electrical short or other problem), then a P1852 diagnostic trouble code will be stored.
How Serious is the Code?
A P1852 DTC is a fairly serious OBDII trouble code, because the underlying problem will prevent gear changes from happening properly. If allowed to continue, this transmission problem will eventually make your vehicle undrivable.
Symptoms of a P1852 include:
- Transmission slipping
- Delayed gear changes
- Erratic shifting
- Burning smell coming from the transmission
- Transmission overheating
- Check engine light
- Dirty transmission fluid/filter
- Clogged hydraulic passages inside the transmission
- Valve body problems
- Damaged or corroded wiring/connectors
- Broken brake band apply solenoid
How to Diagnose the Code?
If your vehicle has a P1852 DTC, then the first thing a mechanic should do is examine the condition of the transmission fluid. Dirty transmission fluid can result in blocked fluid passages inside the transmission, which can negatively affect the performance of the brake band solenoid. The wiring and connectors should also be examined for signs of a short or other damage, along with the connectors on the transmission control module. If no issues are found at this point, then the brake band solenoid could be at fault.
What Repairs Will Fix P1852?
- Change the transmission fluid and filter (service the transmission)
- Replace or repair damage wiring/connectors
- Replace brake band apply solenoid
P1850 – Brake Band Apply Solenoid Circuit
P1851 – Brake Band Apply Solenoid Performance
P1853 – Brake Band Apply Solenoid High Voltage