What does it mean?
P1252 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Throttle Motor Full Pulse Width Modulation in Open Direction and No Motor Current .
Symptoms
- The MIL is on together with a reduced power or throttle warning light
- The engine runs only at idle or a fixed limited speed and ignores the pedal
- No audible throttle sweep from the throttle body when the ignition is switched on
- Severe limp mode, making the vehicle difficult to move under its own power
- Stalling when coming to a stop, or the engine not starting at all
Likely causes
- Open circuit in one of the two throttle motor wires between module and throttle body
- Brushes or windings inside the throttle motor worn open
- Corroded, burnt or backed-out terminals in the throttle body connector
- Blown fuse or an open relay contact in the throttle control supply
- Chafed or broken harness where the loom moves with the engine
- Connector left partly seated after intake or throttle body work
- Throttle control module output stage failure, once the wiring has been proven
How to fix it
- Switch the ignition on and listen for the throttle self-test sweep; silence supports an open motor circuit
- Read live data and compare commanded throttle angle with actual throttle position
- Inspect the throttle body connector for burnt, spread or corroded terminals and confirm it is fully latched
- Unplug the connector and measure the throttle motor winding resistance across its two pins; an open reading condemns the motor
- Check both motor wires back to the module for continuity, and check the supply fuse and relay
- Move the harness by hand during a key-on test to reveal an intermittent open circuit
- Repair the wiring or replace the throttle body assembly as proven, then carry out the throttle relearn procedure and confirm normal pedal response