What does it mean?
P1714 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: A/T Transmission Control Relay Low Battery Voltage .
Symptoms
- MIL on with a transmission warning light
- Transmission dropping into limp mode and staying in one gear
- Harsh engagement and erratic shifts, especially at idle or right after cranking
- Dim lights, slow cranking and a battery warning appearing at the same time
- Fault showing up mainly in cold weather or after the vehicle has stood overnight
- Random module resets with the radio and cluster flickering
Likely causes
- Weak or failing battery, or heavily corroded battery terminals
- Charging system fault: worn alternator, slipping belt or failed voltage regulator
- Corroded or loose transmission control relay socket and terminals
- Relay with high internal contact resistance, dropping voltage across itself
- High resistance in the relay supply wire or its fuse holder
- Poor main ground strap between engine, body and battery
- Excessive current draw elsewhere pulling system voltage down
How to fix it
- Load-test the battery and clean the terminals and ground straps before anything else
- Measure charging voltage at idle and at raised engine speed with the electrical loads switched on
- Perform voltage drop tests across the relay supply path, the fuse holder and the main grounds
- Check the relay socket for heat damage, spread terminals and green corrosion
- Substitute a known good relay, or measure its coil and contact resistance
- Look for a parasitic drain or a high current fault dragging the system voltage down
- Repair the corroded supply wiring, clear the code and confirm transmission behaviour on a road test