P07EA
Transmission Range Control A Circuit Low.
- Generic
- Powertrain
- Generic code
- High severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 7
- AreaTransmission
- EA
- FaultThe specific fault in that area
What it means
P07EA is a generic code meaning the transmission control unit saw a voltage in the Transmission Range Control 'A' circuit that was lower than expected. This circuit is usually linked to the electronic range selection system, such as a range actuator, selector or shift-by-wire module. Which component sits in 'A' circuit depends on the vehicle and transmission, so check the manufacturer's wiring information for your model.
Symptoms
- Warning light on, possibly with a transmission or gearbox warning message
- Car will not select, or is slow to select, Drive, Reverse or Park
- Gearbox stuck in one gear or in limp-home mode
- Gear selector position shown on the dash does not match the selected range
- Engine will not start, or starts only in certain selector positions
- Harsh, delayed or erratic engagement
Possible causes
- Damaged, chafed or shorted-to-earth wiring in the range control circuitlikely
- Corroded, loose or water-damaged connector at the range sensor, actuator or control unitlikely
- Faulty range control actuator, motor or position sensor with an internal short or low outputpossible
- Low battery or supply voltage, or a poor power or earth feed to the transmission control unitpossible
- Faulty transmission control unit or shift module driverrare
- Internal transmission harness or solenoid pack fault (depends on the transmission design)rare
How to diagnose
- Read all stored and pending codes with freeze frame data and note any related battery, communication or range sensor codes before clearing anything.
- Check battery condition and charging voltage, as low supply voltage can set circuit-low faults.
- Inspect the range control wiring and connectors for chafing, water ingress, corrosion, bent pins and poor terminal tension. Check the harness near the gearbox and its mounting points first.
- Using live data, compare the selected range and the range sensor signal against the selector position and look for dropouts or a signal stuck low.
- Check the circuit supply, signal and earth against the manufacturer's wiring diagram and specified voltages, with the connector unplugged where the procedure says so.
- Test the circuit for short to earth and for resistance, wiggling the harness while monitoring the live data to find intermittent faults.
- Test the actuator or sensor against the manufacturer's specification and check the control unit's power and earth feeds.
- Check for relevant technical service bulletins and calibration updates for your model before replacing the control unit.
How to fix
- Repair or replace the damaged wiring section and secure it away from heat and rubbing points.
- Clean, dry and re-seat the affected connectors, or replace corroded terminals and connectors.
- Replace the faulty range actuator, motor or position sensor, then carry out any adaptation or learn procedure the manufacturer requires.
- Restore a healthy battery and charging system and repair poor power or earth connections to the control unit.
- Replace or reprogram the transmission control unit only after the wiring and components have been proven good, and only if the manufacturer's procedure calls for it.
Can I keep driving?
Avoid driving until the fault is diagnosed, as the car may not engage the correct range or hold in Park and could drop into limp mode without warning. If the car is moving normally, only drive it a short distance to a safe place or workshop, and make sure the handbrake is applied when parked.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.