What it means
General electrical fault on the shift solenoid H control circuit — open coil, short to ground or battery, driver feedback outside range.
At a glance
- Usually lights the check-engine light
How it works
Shift solenoid H is an electrically operated valve that controls transmission fluid flow for a particular shift element. The transmission control module sets this code when it detects an electrical fault in the H control circuit, such as an open, short, or out-of-range driver response.
Common causes
Most likely first.
- Open solenoid coil
- Damaged wiring at the transmission connector
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and check for related transmission or voltage codes that may point to a shared power, ground, or connector problem.
- With the ignition off, inspect the transmission connector and the wiring to solenoid H for breaks, chafing, corrosion, fluid intrusion, or loose terminals.
- Check the relevant fuse and circuit power and ground using the wiring information for the vehicle.
- Measure solenoid H coil continuity and check its circuit for shorts or opens, comparing results with the manufacturer’s specification.
- If the wiring and solenoid test correctly, check the control module’s output and connector terminals using the manufacturer’s diagnostic procedure.
Common fixes
- Reconnect, clean, or repair a loose or corroded transmission connector.
- Repair an open, shorted, or chafed wire in the solenoid H circuit.
- Replace shift solenoid H if its coil fails the specified electrical test.
- Repair the relevant power or ground fault, or address a confirmed control module fault.
Can I keep driving?
Drive only as far as needed to reach a safe place if shifts remain predictable; the transmission may shift harshly or enter a protective mode. Avoid towing or heavy acceleration, and stop if the vehicle slips or loses normal gear selection.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.