Generic Fault Code
Free · no signupP0787
Harsh Quick Slamming Shift Actions
System
Transmission
Symptom
Harsh Quick Slamming Shift Actions
Diagnosis & fix steps
LOGIC: Shift/Timing Solenoid Low.
ACTION: Scan for grounded wires along transmission internal case harness line routing paths.
Red Seal field insights
Electrical Logic: Solenoid feedback metrics hold below baseline limits, tricking the TCM into dropping timing dampening.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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Start your free trialRelated Generic fault codes
- P0788Soft Long Slipping Gear Engagements
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- P0785Transmission Slips / Harsh Intermittent Shifts
- P0790Transmission Refuses to Enter Sport Mode Maps
- P0784Engine Flares or Freezes during 4-5 Upshift
- P0801Shifter Allows Accidentally Slipping into Reverse
- P0783Engine Flares or Freezes during 3-4 Upshift
- P0803Manual Shifter Skips 2nd/3rd Gears / Hard Shifts
- P0782Engine Flares or Freezes during 2-3 Upshift