P0524 means the engine control module measured engine oil pressure below its calibrated minimum for the current engine speed and temperature. It sits beside the oil pressure sensor circuit codes P0520 through P0523, but it is different in kind: those report a signal fault, this one reports a measured value. The module believed its sensor and concluded the pressure was too low.
Severity: high until proven otherwise. Can you keep driving? No, not until actual oil pressure has been checked. Low oil pressure destroys bearings and camshafts in minutes. If the oil pressure warning light is on or the engine makes any new noise, stop. If the engine sounds normal, check the oil level and then verify pressure with a mechanical gauge before driving further.
What Mazda found
Mazda's bulletins 01-023/15 (December 2015) and 01-009/16 (April 2016) for the 2012 to 2016 Mazda3, 2013 to 2016 CX-5 and 2014 to 2016 Mazda6 with Skyactiv engines describe a rough idle with the check engine light and P0015 (exhaust camshaft timing over-retarded) together with P0524. The cause: a piece of foreign material stuck on the oil pump pressure relief valve or the oil control valve, dropping oil pressure. The bulletin notes the object may enter and leave, so the light comes on before the rough idle appears. The repair follows a flow chart to clean or replace the relief valve and the oil control valve.
A later bulletin, 01-020/18 (October 2018), covers the 2018 CX-5 with the 2.5 L Skyactiv-G with cylinder deactivation built before May 7, 2018, with P0524 and a master warning; that engine's cylinder deactivation depends on oil pressure, and the bulletin's procedure addresses the pressure supply for it.
The pattern: on engines whose variable valve timing or cylinder deactivation runs on oil pressure, the first symptom of low pressure is a timing code, and P0524 explains it.
Causes, in the order they are found
Low oil level, from consumption or a leak.
Wrong or degraded oil: too thin for the engine, or diluted with fuel from short trips on a direct-injection engine.
A relief valve held open by debris, as in the Mazda cases, or stuck by varnish.
A clogged pickup screen on a neglected engine.
A worn oil pump or worn bearings letting pressure bleed off.
A sensor reading low, less likely for this code than for the circuit codes, but confirmed by a gauge.
The module, last.
A diagnostic order that protects the engine
- Stop and check the oil level. Top up if low and note how much it took.
- Put a mechanical gauge on the engine in place of the sensor. Read at idle hot and at 2,000 rpm against the specification. Normal pressure with the code means the sensor or its circuit; low pressure means a mechanical repair.
- Record companion codes. P0015, P0011 or other cam timing codes beside P0524 on a Mazda Skyactiv point at the relief valve bulletin; a cylinder deactivation code points at that system's oil supply.
- Check oil condition: level, smell of fuel, viscosity on the cap versus what is in the sump.
- Follow the manufacturer's flow chart for the relief valve and oil control valves where a bulletin exists.
- Inspect the pickup, pump and bearings if pressure is low and the valves are clean.
- Replace the sensor only if the gauge reads normal and the sensor's circuit tests good, then clear and verify hot at idle.
Frequently asked questions
Can I drive with a P0524 code?
Not until oil pressure has been checked with a mechanical gauge. Unlike the sensor circuit codes, P0524 reports a measured low pressure, and low pressure damages the engine quickly. Check the level first, then the gauge.
Is P0524 the oil pressure sensor?
Less often than P0520 through P0523, which describe a signal fault. P0524 means the module believed the sensor and found the value too low. A gauge reading normal makes it a sensor problem; a gauge reading low makes it mechanical.
Why does my Mazda have P0524 with P0015?
Because on the Skyactiv engines a drop in oil pressure retards the exhaust camshaft, which sets P0015. Mazda's bulletins trace the pressure drop to foreign material on the oil pump relief valve or the oil control valve, and provide a flow chart for the repair.
How much does it cost to fix P0524?
Topping up oil costs little. A relief valve or oil control valve cleaning or replacement is a moderate job. An oil pump is several hours. Bearings are an engine rebuild, which is why the gauge and the oil level come first.
Related codes
- P0520 to P0523: oil pressure sensor circuit codes; see P0522.
- P0015 / P0011 / P0014: camshaft timing codes, the first symptom of low pressure on engines with oil-driven variable timing.
- P06DD / P06DE: oil pressure control circuit on engines with a two-stage pump.
- P3400 series: cylinder deactivation system codes.
The code number itself tells you the family and the domain; how to read an OBD2 code number explains what each character means.