OBD Code P0789
Shift/Timing Solenoid Intermittent
| Code | P0789 |
| Description | Shift/Timing Solenoid Intermittent |
| Possible Causes | Loose connection|Sticking solenoid |
| Symptoms | Intermittent shift issues |
| System | Transmission |
What Does P0789 Mean?
Shift/Timing Solenoid Intermittent. This diagnostic trouble code (DTC) is stored when the vehicle's onboard computer detects an issue with the transmission.
Code Breakdown
P = Powertrain code
0 = Generic (SAE standard)
How to Fix P0789
Follow these diagnostic steps to identify and resolve the issue. Always start with the simplest checks before moving to more involved repairs.
- Check transmission fluid level and condition first.
- Inspect the transmission wiring harness connector for damage or corrosion.
- Test the shift solenoid resistance with a multimeter — compare to manufacturer spec.
- Command the solenoid on and off with a scan tool and listen for clicks.
- If the solenoid tests bad, it may be accessible by removing the transmission pan (depends on vehicle).
- Replace the solenoid or solenoid pack as needed.
- Clear codes and test drive, monitoring shift quality and timing.
Note: These are general diagnostic guidelines. Some vehicles may have model-specific procedures. Always consult your vehicle's service manual for exact specifications and torque values. If you are not comfortable performing these steps, visit a qualified mechanic.
Frequently Asked Questions
Is P0789 serious?
The severity depends on the underlying cause. Some triggers for P0789 are minor (like a loose gas cap), while others may indicate a more significant problem. We recommend having the code diagnosed with a proper scan tool to determine the exact cause before deciding on urgency.
Can I clear P0789 myself?
You can clear any OBD-II code with a code scanner or by disconnecting the battery for 15-30 minutes. However, clearing the code without fixing the underlying problem will cause it to return, usually within one or two drive cycles. If the code triggered the check engine light, the light will come back on. Fix the root cause first, then clear the code.
How much does it cost to fix P0789?
Repair costs vary widely depending on the root cause. Some fixes are free (like tightening a gas cap) while others can cost several hundred dollars (like replacing a catalytic converter or oxygen sensor). A proper diagnosis with a professional scan tool, not just reading the code, is the first step to getting an accurate repair estimate. Many auto parts stores offer free code reading, but a thorough diagnosis usually requires a mechanic.