P1787
Transmission System Third or Fourth Gear Fault
Severity
🔴 HighCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–278 (est.)
Symptoms
- Car won't shift into 3rd or 4th gear
- The gearbox goes into emergency mode
- Jerks when shifting gears
- Increased fuel consumption
- Check Engine light comes on
Causes
- Shift solenoids malfunction
- Low or contaminated transmission fluid
- Mechanical damage inside the automatic transmission
- Problems with the hydraulic system
- Malfunction of shaft speed sensors
How to Fix
- Check the level and condition of the transmission fluid
- Diagnose the operation of switching solenoids
- Check error codes in the TCM
- Perform a test drive with a scanner connected
- If necessary, replace faulty automatic transmission components