Shift Timing Solenoid High
What does P0788 mean?
The P0788 code means the vehicle's onboard diagnostic system has detected: Shift Timing Solenoid High. This is a moderate severity code.
Common Symptoms
- Check Engine Light illuminated
- Early or harsh shifts
- Transmission shifts at wrong RPM
- Increased fuel consumption
Probable Causes (Ranked by Likelihood)
- Open timing solenoid circuit Very High
- Open ground wire to timing solenoid High
- Failed timing solenoid coil (open) Moderate
- TCM driver circuit fault Low
Step-by-Step Diagnostic Procedure
-
Measure timing solenoid resistance -- OL reading confirms open circuit
-
Check ground wire continuity
-
Inspect connector for disconnection
-
Check wiring from TCM to solenoid for breaks
-
Replace solenoid if coil is open
Frequently Asked Questions
Can I drive with code P0788?
Drive short distances only. Shift malfunction codes indicate the transmission is not shifting correctly, which can cause further damage.
What does P0788 mean?
Shift Timing Solenoid High. This means the TCM has detected that a shift event is not occurring as expected. The cause can range from a faulty solenoid to internal transmission wear.
Will a transmission flush fix P0788?
A fluid flush alone rarely fixes shift malfunction codes. However, if the fluid is contaminated, a flush combined with solenoid replacement may resolve the issue. Never flush a transmission with heavily burnt fluid, as it can dislodge debris and cause further damage.