P1786
Transmission System Second or Third Gear Fault
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–167 (est.)
Symptoms
- Incorrect gear shifting
- Delays when switching to second or third gear
- Power dips
- Increased noise during gearbox operation
- Switching to emergency mode
Causes
- Low or contaminated transmission fluid
- Shift solenoids malfunction
- Problems with the hydraulic block
- Wear of mechanical components of the gearbox
- Problems with electronic control (TCM)
How to Fix
- Check the level and condition of the transmission fluid
- Diagnose the gearshift solenoids
- Check the hydraulic unit for leaks and damage
- Inspect the mechanical components of the transmission
- Check electrical connections and wiring harness