What it means
The control module detects a low electrical level in the shift solenoid E control circuit.
At a glance
- Usually lights the check-engine light
How it works
Shift solenoid E is an electrically operated valve that controls transmission fluid flow during particular shifts. The transmission control module monitors the E solenoid circuit and sets P0985 when its signal is lower than expected, which can point to a short to ground or damaged wiring.
Common causes
Most likely first.
- Short to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
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
- Use freeze-frame and live transmission data to identify when P0985 set, and check for related E solenoid or shared circuit codes.
- Inspect the E solenoid harness for chafed insulation touching ground, and check its connector for corrosion, loose pins, or damage.
- Isolate the circuit using the manufacturer's procedure and compare E solenoid coil resistance with the manufacturer's specification.
- Test the E control wire for a short to ground, excessive resistance, or an intermittent fault while gently moving the harness.
- If the solenoid and wiring pass, inspect the control module connector and E circuit terminal for a poor or grounded connection.
Common fixes
- Repair chafed E solenoid wiring that is contacting ground.
- Clean or replace corroded or damaged terminals in the E circuit.
- Replace shift solenoid E if its coil fails the manufacturer's specification.
- Repair a confirmed fault in the control module connector or circuit.
Can I keep driving?
Avoid towing and hard acceleration, and keep trips short if the transmission is shifting poorly or slipping. Continued slipping can overheat or damage the transmission; stop if it becomes stuck in one gear or unsafe to control.
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.