What does it mean?
P1572 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: TCS Active Circuit Low Voltage Too Long .
Symptoms
- Traction control warning lamp stays on continuously
- Engine power is held back permanently, so the vehicle accelerates very poorly
- Check engine light on, often with ABS codes stored as well
- Throttle response feels muted even on dry roads with no wheelspin
- Transmission may hold lower gears or shift oddly because torque is being limited
- Symptoms do not change when driving carefully, which distinguishes this from a genuine slip event
Likely causes
- Signal wire chafed and shorted to ground along the harness route
- Traction control module output stuck on because of an internal fault
- Faulty or dirty wheel speed sensor making the system believe one wheel is constantly slipping
- Mismatched tyre sizes or a much smaller spare fitted, producing a permanent speed difference
- Corroded connector at the ABS or traction control module
- Poor ground causing the signal reference to sit low
- Damaged input circuit inside the engine control module
How to fix it
- Read the ABS and traction module codes first and repair any wheel speed sensor faults they point to
- Compare all four wheel speed values in live data while driving slowly and look for one reading that does not match
- Check tyre sizes and pressures on all four corners, including a temporary spare
- Measure the voltage on the traction active line with the engine running; a permanently low reading confirms the fault
- Disconnect the traction control module and see whether the signal releases, which isolates the module from the wiring
- Inspect the harness for chafing and repair any short to ground
- Replace the traction control module only after the wiring and sensors have been proven good