'Shift timing solenoid' means different parts: on GM's 4L60-E the 3-2 downshift solenoid that times the band apply on that downshift, on Aisin five-speeds (GM, Saab) the linear valve SLS that sets clutch pressure during the shift, and on the 2017–18 Genesis G80/G90 with shift-by-wire the on/off solenoids that engage drive (A) and reverse (B). Only Hyundai/Genesis is documented using solenoid B, and only with the base code P078A. No manufacturer document available to us uses this code; the description follows solenoid A (P0788: short to positive or overcurrent, on GM's Aisin-type unit above 1356 mA for 2 s). Warning lamp and limp mode follow; the opposite is P078C.
Medium severity. Can I keep driving?Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
Symptoms
- Warning lamp
- Limp mode
Most likely causes
- Short to positive
- Winding short
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P078D means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 7: Transmission
- 8D: Specific fault in that system
Frequently asked questions
Can I keep driving with code P078D?
Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
What causes code P078D?
The most common causes are: short to positive; winding short.
Related codes
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.