The P0773 code is a generic OBD-II diagnostic trouble code indicating “Shift Solenoid ‘E’ Electrical.” It means the powertrain or transmission control module detected an electrical fault in the shift solenoid E circuit.
This code does not automatically prove the solenoid has failed. Diagnosis requires inspecting the wiring, testing the solenoid coil resistance, and verifying the control circuit before replacing components.
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Key Takeaways
- The P0773 code indicates the control module detected an electrical fault in the shift solenoid E circuit.
- Possible causes include a failed solenoid coil, an open or shorted circuit, or damaged wiring harnesses.
- Diagnosis involves inspecting the transmission harness, testing the solenoid resistance, and checking the control module signals.
- Repairs may involve repairing wiring, replacing the confirmed failed solenoid, or addressing internal transmission harness issues.
P0773 Code Description and Implications
The P0773 code indicates that the control module detected an electrical malfunction in the Shift Solenoid “E” circuit. This generic category of diagnostic trouble codes applies to vehicles with electronically controlled automatic transmissions.
Shift solenoids control the flow of hydraulic fluid to engage specific clutch packs and bands for gear changes. The control module commands the solenoid and monitors the electrical circuit for faults.
When the module detects an open circuit, a short to ground, or a short to voltage in the Shift Solenoid E circuit, it stores this code and may inhibit certain gear shifts.
Common Causes of the P0773 Code
A failed Shift Solenoid E coil is a possible cause. An internal open or short within the solenoid winding will cause the control module to detect an electrical circuit fault.
Damaged wiring, chafed insulation, or corroded connectors in the transmission harness will interrupt the circuit or introduce a short, triggering the electrical malfunction code.
In some applications, an internal failure of the transmission wiring harness or a faulty control module driver circuit can also cause this electrical fault.
Symptoms Associated With P0773
An illuminated Check Engine Light is expected once the monitor detects the electrical circuit fault. MIL behavior varies by application, but the light commands when the electrical fault is verified.
You may experience harsh shifts, delayed shifts, or the transmission becoming stuck in a single gear as a fail-safe measure to protect the internal clutches.
In some applications, the transmission may enter a limp mode, restricting gear selection and reducing overall vehicle performance.
Diagnosing the P0773 Trouble Code
Diagnosis must begin by confirming the exact factory definition and checking for related transmission or solenoid circuit codes. Record freeze-frame data to note the vehicle speed and commanded gear when the code set.
Perform a thorough visual inspection of the external transmission wiring harness and connectors. Look for chafed wires, corrosion, or fluid intrusion in the main case connector.
Use a multimeter to measure the resistance of Shift Solenoid E at the transmission case connector and compare it to the exact manufacturer specification.
If the external harness and solenoid resistance are correct, the fault may lie within the internal transmission wiring harness or the control module itself.
Repairing the P0773 Issue
Repairs must follow confirmed diagnosis. If the external wiring harness is found to be damaged or shorted, repair the circuit and secure the harness away from hot or moving components.
If resistance testing confirms Shift Solenoid E is internally open or shorted, replace the solenoid using a component meeting the exact vehicle specification.
If the internal transmission harness is damaged, dropping the transmission pan or removing the valve body may be required to replace the internal wiring.
Cost Considerations for P0773 Repairs
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Replacing an externally mounted shift solenoid involves minimal parts and moderate labor expenses.
If the solenoid is located inside the transmission pan on the valve body, or if the internal harness requires replacement, the labor costs will increase due to fluid service and disassembly.
Prevention Strategies for Future Occurrences
Inspecting exposed transmission wiring harnesses and electrical connectors during routine under-vehicle service can help identify developing insulation damage or moisture intrusion before it causes a circuit fault.
Addressing transmission fluid leaks promptly helps prevent fluid from wicking into electrical connectors and disrupting the sensitive solenoid circuits.
Some electrical solenoid failures occur due to normal component aging and high-temperature transmission environments, and cannot be reliably prevented.
Troubleshooting Tips and Best Practices
Do not attempt to fix a P0773 code by simply replacing the shift solenoid without checking the wiring and connector first. Harness damage near the transmission case is a frequent cause of electrical faults.
Always verify the exact physical location and resistance specification of Shift Solenoid E. On some applications, the solenoids are mounted externally, while on others, they are located inside the pan.
Check for technical service bulletins for your exact vehicle application, as some manufacturers release updated transmission wiring harnesses or revised solenoid designs to address chronic electrical issues.
More OBD-II Codes
| P0765 | P0766 | P0770 | P0771 |
| P0761 | P0758 | P0775 | P0776 |
| P0777 | P0778 | P0780 | P0783 |
| P0757 | P0760 | P0785 | P0747 |
| P0741 | P0743 | P0733 | P0734 |
| P0700 | P0715 | P0722 | P0730 |
Frequently Asked Questions
Is the P0773 code generic or manufacturer-specific?
Yes, P0773 is a generic SAE OBD-II diagnostic trouble code. However, the exact transmission architecture and solenoid testing procedures vary by manufacturer and vehicle application.
Will a P0773 code cause my transmission to slip?
It can cause shifting issues. If the solenoid circuit is faulty, the transmission may default to a limp mode, experience harsh shifts, or become stuck in a single gear to protect internal components.
Does a P0773 code mean my shift solenoid E is broken?
Not necessarily. While the solenoid coil can fail internally, the code is also frequently caused by damaged wiring, a corroded connector, or a shorted circuit. Proper electrical testing is required first.
Can low transmission fluid cause a P0773 code?
No. P0773 specifically indicates an electrical circuit fault, such as an open or short. Low fluid typically triggers hydraulic pressure or gear ratio performance codes, not electrical circuit malfunctions.
Can I clear the P0773 code without fixing the problem?
Clearing the code only resets the warning light. If the underlying wiring fault, short circuit, or failed solenoid coil remains, the monitor will detect the electrical fault immediately and turn the light back on.
What Should You Do About the P0773 Code?
Confirm the exact factory definition and check for related transmission codes for your specific vehicle application. Follow the applicable manufacturer diagnostic procedure to verify whether the fault lies in the external wiring, the solenoid coil, or the internal harness.
Once testing confirms the root cause, repair or replace the confirmed failed component in the relevant system and components, then retest the transmission operation and clear the codes.
