P0CDA
Drive Motor A Position Sensor Circuit C.
- Generic
- Powertrain
- Generic code
- High severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- C
- AreaHybrid propulsion
- DA
- FaultThe specific fault in that area
What it means
P0CDA means the control unit has detected a fault in the circuit of the position sensor (often a resolver) for drive motor A, specifically the circuit the standard labels 'C'. The motor control system uses this signal to know rotor position and time the motor's phase currents. It set the code because the signal was missing, out of range, implausible or failed a self-check. The exact sensor layout and what 'Circuit C' covers depend on the model and system design.
Symptoms
- Hybrid or EV system warning light on the dash
- Reduced power or limp-home mode
- Car will not enter Ready mode or will not move
- Rough, jerky or sudden loss of drive from the electric motor
- Engine starting more often than usual on a hybrid, or failure to restart after stopping
- Other drive motor or inverter fault codes stored alongside
Possible causes
- Damaged, chafed or corroded wiring to the motor position sensor, including open circuit, short circuit or shorting to other wireslikely
- Poor connection at the sensor or control unit connector, such as corrosion, water ingress or a loose pinlikely
- Faulty drive motor position sensor or resolverpossible
- Electrical interference or a damaged shield on the sensor signal wiringpossible
- Low or unstable 12 V supply upsetting the sensor or control unitpossible
- Fault inside the inverter or motor control unit's sensor interfacerare
- Mechanical damage or misalignment of the sensor or rotor position referencerare
How to diagnose
- Read all stored and pending codes and note the freeze frame data, including vehicle state and speed when the fault set, and check for related motor, inverter or communication codes.
- Check the condition of the 12 V battery and charging, since low voltage can cause false sensor faults.
- Check for relevant technical bulletins or known software updates for the model and system.
- Following the manufacturer's high-voltage safety procedure, which must only be done by a suitably trained technician, visually inspect the sensor wiring and connectors for damage, chafing, heat, moisture or corrosion.
- Check the sensor harness for continuity, short to earth, short to supply and short between wires, using the manufacturer's wiring diagram and pin-out.
- Measure the sensor's coil resistances or signal output against the manufacturer's specification, as values vary by model.
- Check the sensor signal live while the motor turns, if the manufacturer's procedure allows, to look for dropouts or noise.
- Inspect the sensor and motor housing for fluid ingress or mechanical damage, then clear the code and road test to see if it returns.
How to fix
- Repair or replace damaged wiring, and restore any shielding or earth connections to the manufacturer's standard.
- Clean, repair or replace corroded or loose connectors and terminals, and fix any source of water ingress.
- Replace the drive motor position sensor or resolver if it fails testing, following the manufacturer's procedure, including any required position learning or calibration.
- Correct 12 V battery or charging faults that cause unstable supply voltage.
- Replace or reprogram the inverter or motor control unit only after the wiring and sensor are proven good, or if a known software fault applies.
Can I keep driving?
Avoid driving until it has been inspected. A loss of motor position data can cause sudden loss of drive or a failure to move, and it can lead to further damage. If the car still runs, limit use to getting it safely to a workshop.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.