P0522 means the engine control module saw the voltage from the engine oil pressure sensor or switch below its minimum acceptable value. It is the "circuit low" member of the P052x family: P0520 is the general circuit code, P0521 is range or performance, P0522 is low, P0523 is high. On a vehicle with a variable sensor, "low" means the signal voltage sat near zero. On a vehicle with a simple switch, it means the switch reported the state that corresponds to no pressure, which on most designs is the switch closed to ground.
Severity: it depends on one measurement. Can you keep driving? Not until that measurement is made. If the oil pressure warning light is on and the engine sounds normal, the fault is probably electrical, but "probably" is not good enough for a decision that can cost an engine. If there is any valvetrain noise, a knock, or the light came on with a hot engine at idle, stop and check the oil level, then check actual pressure with a mechanical gauge. Once a gauge shows normal pressure, the code becomes a wiring and sensor problem and the vehicle can be driven while it is chased.
Sensor or switch: what the vehicle has decides the diagnosis
A switch is a two-terminal device (or one terminal, grounding through its threads) that closes or opens at a fixed pressure, typically a few psi. It drives the warning light and gives the module a yes-or-no answer. On a switch, P0522 means the module saw the "no pressure" state while the engine was running above a calibrated speed.
A sensor is a three-wire device with a 5-volt reference, a ground and a signal that rises with pressure, usually between about 0.5 V at zero and 4.5 V at maximum. It drives a gauge and lets the module protect the engine and, on many engines, run cylinder deactivation, variable valve timing and oil life logic. On a sensor, P0522 means the signal sat below its floor, which is what a short to ground or an open signal wire looks like.
Several engines use both, or a combined sensor and switch in one housing. The Chrysler 3.6 L Pentastar in Jeep Wrangler, Grand Cherokee, Chrysler Pacifica and the Ram 1500 uses a sensor screwed into the oil filter housing on top of the engine, and it is the part owners on the Jeep and Chrysler forums replace first when P0522 appears, sometimes twice, before finding a ground or wiring problem.
Where the wiring fails: the 2019 Silverado and Sierra case
The clearest manufacturer documentation of P0522 as a wiring code is General Motors' preliminary information PIT5677 (first issued August 2019, revised through 2021) and the bulletin that replaced it, 21-NA-149 (November 2021, updated December 2023). The original applies to 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 with the 2.7 L L3B turbo four-cylinder. Customers reported a check engine light, no start, no crank, rough running, reduced engine power, erratic speedometer and blown fuses, and the stored codes could be any combination of a long list that includes P0521, P0522 and P0532. The cause GM gives is engine harness contact with under-hood components, and it names the spots to inspect:
- where the harness crosses the top of the camshaft carrier cover
- at the lower air cleaner housing
- at the inlet radiator hose bracket and the left front coil spring stud
GM adds a note that matters for every intermittent electrical code: under normal driving the engine rocks in its mounts, so the harness may touch the bracket only while driving, and the contact may not be visible with the engine off. The correction is to open the harness with a seam ripper, find the damaged conductor, repair it wire to wire, and wrap the harness at every listed point with woven polyester anti-abrasion tape.
The lesson generalizes. An oil pressure sensor's signal wire shorted to ground by a chafe sets P0522 with a perfectly good sensor, and the code will return after a sensor replacement. Whenever P0522 arrives with other unrelated codes, or with blown fuses, suspect the harness before the sensor.
Causes, in the order they are found
A failed sensor. Oil pressure sensors do fail, and the diaphragm type used on many engines fails by leaking oil into its own electronics, which pulls the signal low. Oil weeping from the sensor body or filling its connector is a diagnosis. On the 3.6 L Pentastar this is the most common single cause.
A chafed or pinched signal wire. As in the GM case, and on any engine where the harness runs near a bracket, the engine rocks and the insulation wears through. Look for other codes and for symptoms that come and go with engine movement.
A connector problem. Oil in the connector, corrosion, a pushed-back terminal, or a seal that has hardened. The sensor sits where oil leaks land.
A ground or reference problem. A sensor's ground with resistance in it, or a reference circuit shared with other sensors that is dragged down, produces low readings on several sensors at once. If P0522 sits beside codes on other three-wire sensors, the fault is shared.
Actual low oil pressure. Low oil level, a worn pump, a stuck relief valve, a clogged pickup screen, or badly diluted oil. This is the cause that damages the engine, and it is the one the mechanical gauge rules in or out.
The module. Last on the list, after the gauge, the sensor and the wiring have all been checked.
A diagnostic order that protects the engine first
- Check the oil level and listen. Low level or any new noise means stop and put a gauge on it before anything else.
- Put a mechanical gauge on the engine. Remove the sensor or switch, thread in a gauge, and read pressure at idle and at 2,000 rpm, hot. Compare with the manufacturer's specification. Normal pressure makes this an electrical code; low pressure makes it a mechanical repair and the sensor was telling the truth.
- Record every code and the freeze frame before clearing. Companion codes point at a harness; a lone P0522 with oil in the sensor connector points at the sensor. The freeze frame shows engine speed and temperature at the fault.
- Pull the connector and look. Oil inside, corrosion, loose terminals. Clean and repair before testing.
- Test the circuit, key on, sensor unplugged. About 5 V on the reference, near 5 V on the signal (the module pulls it up), under 0.1 V of drop on the ground. Signal at zero with the sensor unplugged is a signal wire shorted to ground somewhere in the harness, and no sensor will fix it.
- Inspect the harness where it moves. Follow GM's list on a 2019 Silverado or Sierra 2.7 L; on any other engine, follow the harness from the sensor to the module and look at every point where it crosses a bracket or an edge, with the engine rocked by hand.
- Replace the sensor only after the circuit has passed, then clear the code and verify hot at idle, where oil pressure is lowest and the code most likely to return.
What P0522 does not tell you
It does not say whether oil pressure is low; it says the signal was. That is why the gauge comes first, and why the code cannot be dismissed as electrical until the gauge says so. It also does not say where on the circuit the low signal originates. The sensor is the part that can be tested by unplugging it; the general principle is covered in what a trouble code does not tell you. A flashing check engine light with this code is a misfire and a separate problem; see why a flashing light means stop.
Frequently asked questions
Can I drive with a P0522 code?
Not until actual oil pressure has been checked with a mechanical gauge. If the gauge shows normal pressure, the code is electrical and the vehicle can be driven while the wiring and sensor are diagnosed. If the oil light is on and the engine makes any new noise, stop the engine.
Is P0522 always the oil pressure sensor?
No. The sensor is the most common single cause, but a chafed signal wire shorted to ground sets the same code with a good sensor, which is what GM documented on the 2019 Silverado and Sierra 2.7 L. Test the signal wire with the sensor unplugged: if it reads near zero instead of about 5 V, the harness is the fault.
Why did P0522 come back after I replaced the sensor?
Usually because the fault was in the wiring, the connector or the ground, not the sensor. Oil in the connector, a rubbed wire, or a poor ground each returns the code with a new part installed. Run the unplugged circuit test and inspect the harness where the engine rocks.
How much does it cost to fix P0522?
An oil pressure sensor is an inexpensive part with a short replacement time on most engines. A harness repair is usually an hour or two. The expensive outcome is real low oil pressure, which is why the mechanical gauge comes before any part is ordered.
Related codes
- P0520 / P0521: oil pressure sensor circuit and range or performance. The reading is present but implausible.
- P0523: oil pressure sensor circuit high. The opposite fault, usually an open ground or a signal shorted to power.
- P0524: engine oil pressure too low. Set when the module believes the pressure itself is low, not just the signal.
- P0532: A/C refrigerant pressure sensor circuit low, listed with P0522 in GM's harness bulletin because both share the chafed harness.
- P06DD / P06DE: engine oil pressure control circuit stuck off or on, on engines with a two-stage oil pump.
The code number itself tells you the family and the domain; how to read an OBD2 code number explains what each character means.