Engine code
P0520: Engine oil pressure sensor circuit problem
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $0 | $0 |
| Labor: 0.5 to 1.5 hours × $125 to $175 an hour | $63 | $263 |
| Fees: shop supplies, disposal, diagnostics | $0 | $25 |
| Total, rounded | $60 | $290 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in Boston, $31.54 an hour, times 4 to 5.5 to cover what a shop bills (overhead, tools, insurance, profit). Parts are a band from budget aftermarket to the manufacturer part. Full method.
Not a repair shop, estimates only. Typical range, estimate. Not a quote. Your car, parts and shop change the number.
This is the range for the most common fix, diagnostic scan (check engine light). Which repair your car needs depends on a proper diagnosis.
The oil pressure sensor or switch sends a signal that the computer cannot make sense of. This could be a failed sensor or damaged wiring, but it can also reflect real low oil pressure. Because the dash light can look the same in both cases, the oil level should be checked first.
- Safe to drive?
- Short trips only
- Most common cause
- Failed oil pressure sensor or switch
Check the oil level right away. If the oil light is on or you hear ticking or knocking, stop driving, since low oil pressure destroys engines quickly.
What you may notice
- Oil warning light or gauge acting strangely
- Check-engine light
- Often none
Common causes, most likely first
- Failed oil pressure sensor or switch
- Wiring or connector fault
- Low or dirty oil
- Actual low oil pressure from engine wear
Check this first
Check the dipstick for level and condition before anything else. Ask for a mechanical oil pressure test if the shop is unsure whether the sensor or the engine is at fault.
Other repairs that sometimes fix P0520
| Repair | Typical range, Boston |
|---|---|
| Oil and filter change | $80 to $190 |
| CAN bus wiring repair | $190 to $1,275 |
Before you pay
- Ask the shop what test showed this part is the cause, not just that the code appeared.
- Ask for parts and labor listed separately, and for the hours.
- Ask for a written OK before any extra work. Massachusetts rules require written authorization before repairs.
Got a quote already? Check it against the range. Want to see if your car has a recall tied to this problem? Check recalls by VIN.
Need to read a code yourself? OBD-II scanners on eBay (affiliate link, disclosure).
P0520 questions
Is the sensor or the engine the problem?
A mechanical pressure gauge test answers that question. If the real pressure is fine, the sensor is at fault. If it is low, the engine needs deeper work, so the test is worth the diagnostic fee.
Can I just ignore the oil light?
No. A bad sensor and truly low pressure look the same on the dash. If the oil light is on, stop and check the oil level, and do not keep driving if the light stays on or you hear knocking.
What oil should I use?
Use the grade listed in your owner manual. A wrong thickness can change pressure readings and also affect wear over time, so avoid guessing or mixing grades when you top off.
How much does it cost to fix P0520?
The most common fix, diagnostic scan (check engine light), has a typical range of $60 to $290 in Boston. It is an estimate built from parts prices and local labor wages, not a quote. Your car and shop change it.
Related codes
- P0521: Oil pressure sensor signal out of range
- P0522: Engine oil pressure sensor reads too low
- P0523: Engine oil pressure sensor reads too high
More engine codes
Code meaning written in our own words. Some codes mean different things on different makes, so check your scan tool or manual. Not a repair shop, estimates only.