P0521 on RAM
Engine Oil Pressure Sensor/Switch Range/Performance
P0521 on RAM vehicles indicates engine oil pressure sensor/switch range/performance. Au7o has documented this code across 2 RAM models — most commonly on 1500, ProMaster City. This code indicates the engine oil pressure sensor or switch is sending a reading that is implausible or out of its normal operating range — for example, the value doesn't match what the engine's speed and conditions should produce. Unlike a simple circuit fault, this means the signal is present but doesn't make sense (range/performance). It can be caused by a failing sensor, wiring issues, or by genuinely abnormal oil pressure. Because oil pressure protects the engine, a true low-pressure reading should be confirmed and taken seriously. Typical repair costs on RAM range from $2,500 to $14,000, depending on the specific model and root cause.
Common Causes of P0521
- •Faulty or worn oil pressure sensor/switch
- •Low engine oil level or actual abnormal oil pressure
- •Wiring or connector corrosion/damage at the sensor
- •Sludge or debris affecting the sensor reading
- •Use of incorrect oil viscosity
- •Failing oil pump
- •Poor electrical ground
P0521 on RAM by Model
RAM 1500(2 issues)
- 3.0L EcoDiesel Bottom-End Failure — Spun Main/Rod Bearing and Broken Crankshaft2014-2023
The 3.0L EcoDiesel V6 suffers documented bottom-end failures: the main bearings (most common) and connecting-rod bearings wipe out, dropping oil pressure to the rods, spinning a rod bearing and sometimes snapping the crankshaft if driven on. Factory main-bearing clearances are very tight (~0.0015 in), so the combination of high load at low rpm, torsional vibration, and hot thin oil wipes a bearing. A contributing failure is the plastic-bodied oil cooler/check valve, which can fail under sustained high oil temperature (especially towing) and contaminate the oil — accelerating bearing damage. These are catastrophic, often-low-mileage failures distinct from the previously covered EGR-cooler and CP4 fuel-pump issues.
- 5.7L HEMI MDS lifter collapse and camshaft lobe wear ("HEMI tick" leading to engine damage)2014-2023
The 5.7L HEMI (Gen III) with the Multi-Displacement System (MDS) is well documented for roller-lifter failure that progresses into camshaft lobe damage. The MDS deactivation lifters and the engine's circuitous oiling path (oil routed through the deck, head gasket, and rocker shaft to the lifter bore) leave lifter bores oil-starved at low RPM. Improperly hardened lifter roller/needle assemblies allow needles to breach the surface hardening, spalling the roller and then wiping the cam lobe. It starts as a rhythmic cold-start/idle tick and can end in metal debris throughout the engine and total failure, sometimes at very low mileage. This is the subject of the Petro et al. v. FCA US LLC class action (D. Del., No. 1:22-cv-00621) covering 2014+ 5.7L and 6.4L HEMI engines. FCA revised the lifter design around 2018 (larger needles) but failures continued to be reported afterward.
RAM ProMaster City(1 issue)
- 2.4L Tigershark MultiAir II (ED6) Excessive Oil Consumption from Piston Ring Coking Leading to Engine Seizure2015-2022
The only engine offered in the ProMaster City is the 2.4L Tigershark MultiAir II (FCA engine family ED6), the same long block used in the Jeep Cherokee/Renegade/Compass, Dodge Dart and Fiat 500X. The oil-control piston rings coke up and lose their seal, so oil passes into the combustion chamber and is burned. Consumption of 1-2 quarts per 1,000 miles is routinely reported by ProMaster City owners, and because the van has no oil level gauge and the low-oil warning strategy is late, delivery and fleet vans run the sump down between service intervals and seize or spin a bearing with little warning. Forum reports include a 2016 ProMaster City needing a complete engine replacement at roughly 61,000 miles. This is NOT the 3.0L diesel or 3.6L Pentastar story from the full-size ProMaster - that van's engines are unrelated and this defect does not apply to them.
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View P0521 across all makes →Frequently Asked Questions
What does P0521 mean on RAM?▼
P0521 stands for "Engine Oil Pressure Sensor/Switch Range/Performance." This code indicates the engine oil pressure sensor or switch is sending a reading that is implausible or out of its normal operating range — for example, the value doesn't match what the engine's speed and conditions should produce. Unlike a simple circuit fault, this means the signal is present but doesn't make sense (range/performance). It can be caused by a failing sensor, wiring issues, or by genuinely abnormal oil pressure. Because oil pressure protects the engine, a true low-pressure reading should be confirmed and taken seriously. On RAM specifically, this code is documented across 2 models.
What causes P0521 on RAM vehicles?▼
Common causes on RAM: Faulty or worn oil pressure sensor/switch, Low engine oil level or actual abnormal oil pressure, Wiring or connector corrosion/damage at the sensor, Sludge or debris affecting the sensor reading, Use of incorrect oil viscosity. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0521 on a RAM?▼
Repair costs on RAM range from $2,500 to $14,000, depending on the specific model and root cause.
Which RAM models have P0521 documented?▼
Au7o has documented P0521 on 2 RAM models: 1500, ProMaster City.