* Oil Pressure Sensor: This sensor monitors the oil pressure in your engine. A faulty sensor could be sending a false low-pressure signal to the light, especially under increased load (like when braking). Braking puts stress on the engine's systems, and if the sensor is failing, it might only show a problem under this added stress.
* Wiring to the Oil Pressure Sensor: A short circuit or broken wire in the wiring harness leading to the sensor could also cause an intermittent false signal to the oil light. The vibration from braking could exacerbate a loose connection.
* Less Likely (but possible): While less probable given you say the oil level is full, a very clogged oil pickup tube could restrict oil flow enough to cause low pressure only when the engine is under the extra stress of braking. This is less likely because it would usually show oil pressure problems more consistently, not just during braking.
What to do:
1. Check the oil level again: Even though you say it's full, double-check using the dipstick. Make sure you're checking it correctly (engine off, level ground, wait a few minutes after turning the engine off).
2. Check the oil pressure: A mechanic can easily test the actual oil pressure using a gauge. This definitively determines if the pressure is truly low or if it's just a sensor issue.
3. Inspect the wiring: If a mechanic confirms low oil pressure isn't the problem, they should inspect the wiring harness to the oil pressure sensor for any damage, breaks, or loose connections.
4. Replace the Oil Pressure Sensor: This is the most likely solution if the pressure test is normal. It's a relatively inexpensive and easy repair.
Do not continue driving the van with the oil light on. Driving with low oil pressure can severely damage your engine. Even if it's a sensor problem, it's best to have it checked out by a mechanic as soon as possible to prevent potential engine damage.
