P0985
Shift Solenoid E Control Circuit Low.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 9
- AreaTransmission
- 85
- FaultThe specific fault in that area
What it means
P0985 is a generic transmission code meaning the control unit has detected a low voltage or signal level in the control circuit for shift solenoid E. The transmission control module drives the solenoid and monitors the circuit, and it set the code when the voltage was lower than expected, which points to a short to ground, a wiring fault or a faulty solenoid or module driver. Which gears or functions solenoid E controls depends on the make, model and transmission.
Symptoms
- Gearbox warning light or engine management light on
- Transmission stuck in one gear (limp mode) or limited gear selection
- Harsh, delayed or flared gear changes
- Failure to select certain gears or no engagement of a particular ratio
- Poor fuel economy or reduced performance
- Torque converter lock-up not working on some transmissions
Possible causes
- Wiring harness chafed or shorted to ground between the solenoid and the transmission control modulelikely
- Faulty shift solenoid E with low internal resistance or internal shortlikely
- Damaged or corroded connector or internal transmission harness connector, including fluid ingresslikely
- Contaminated or degraded transmission fluid affecting the solenoid or valve bodypossible
- Faulty transmission control module driver circuitpossible
- Low or poor system voltage or a bad earth affecting the control modulepossible
- Outdated control module software where the manufacturer has issued a correction for this faultrare
How to diagnose
- Read all stored and pending codes and freeze frame data, noting when the fault set and whether other transmission codes are present
- Check the transmission fluid level, condition and smell, following the manufacturer's procedure for that gearbox
- Inspect the wiring and connectors between the transmission and the control module for chafing, melted insulation, corrosion and moisture
- Check battery voltage, charging voltage and main earths to rule out supply problems
- Measure the resistance of solenoid E against the specification for that model and compare with the other solenoids
- Test the solenoid circuit for a short to ground and for continuity with the connector unplugged, using the wiring diagram
- Command the solenoid with a suitable scan tool and watch the response and the circuit voltage
- Check for manufacturer software updates or technical bulletins for the transmission and fit if applicable
How to fix
- Repair or replace the damaged wiring or connector, sealing it against moisture
- Replace the faulty shift solenoid E or the solenoid pack, following the model procedure
- Replace the internal transmission harness or connector if it is damaged or leaking fluid
- Change the transmission fluid and filter if it is contaminated, using the specified fluid
- Repair the power supply or earth fault if voltage problems are found
- Replace or repair the transmission control module if the driver circuit is proven faulty, then adapt or program it as required
Can I keep driving?
The car can usually be driven carefully for a short time, but the gearbox may be in limp mode with restricted gears. Get it checked soon, as continued driving with harsh or incorrect shifts can cause further transmission wear.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.