What does it mean?
P1886 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: A/T Driven Pulley Speed Sensor Circuit Malfunction .
Symptoms
- Malfunction indicator lamp on and a transmission fault message
- Speedometer may read incorrectly or drop to zero on some vehicles
- Erratic ratio changes, surging or a feeling that the transmission cannot decide on a ratio
- Fixed-ratio limp operation with reduced performance
- Harsh or delayed engagement when pulling away
- Fault often appears intermittently before becoming permanent
Likely causes
- Failed driven pulley speed sensor
- Metal particles from belt or pulley wear sticking to the sensor tip
- Wiring fault in the signal, supply or ground circuit — chafe, corrosion or a broken conductor
- Fluid or moisture inside the transmission connector
- Sensor not seated fully, or its O-ring damaged, changing the air gap
- Damaged reluctor teeth on the secondary pulley
- Faulty input circuit in the transmission control module
How to fix it
- Read codes and freeze frame, and note whether the fault is intermittent
- Compare driven pulley speed with vehicle speed and drive pulley speed in live data on a road test
- Inspect and clean the transmission connector; look for oil wicking into the harness
- Measure supply voltage, ground and signal output at the sensor connector
- Remove the sensor and inspect the tip and its seat for metal debris and damage
- Repair the harness or replace the sensor, then confirm a stable signal across the full speed range
- If significant metal debris was present, investigate the internal condition of the CVT before releasing the vehicle