Trouble codes › By vehicle › Ram 1500
Common check-engine codes on the Ram 1500
2009-2023
Ram 1500s with the 5.7L Hemi V8 and the 3.6L Pentastar V6 have a few well-known problems: Hemi lifter and camshaft wear (often with a tick and misfire), EVAP leaks and, on the 3.6L, oil filter housing leaks that soak the oil pressure sensor.
Most common: P0300, P0456, P0420, P0520, P0128, P0171.
Known problems on the Ram 1500
- Chrysler 3.6L Pentastar oil filter housing leak and oil pressure sensor (P0520, P0521)
- 5.7L Hemi lifter and camshaft wear ("Hemi tick") (P0300, P0301, P0302, P0303)
P0300 Random/Multiple Cylinder Misfire Detected
P0300 means the engine is misfiring in more than one cylinder, often from worn plugs or coils, a vacuum leak or low fuel pressure.
On the Ram 1500: On the 5.7L Hemi, a misfire with a ticking noise is a well-known sign of a failed lifter or worn camshaft lobe, linked to the Multi-Displacement System. Rule out plugs and coils first; the Hemi uses two plugs per cylinder.
P0300: causes, can I keep driving, and what to check first →
P0456 Evaporative Emission System Leak Detected (Very Small Leak)
P0456 means the EVAP system has a very small leak, often a gas cap that isn't sealing perfectly.
On the Ram 1500: EVAP very small leaks (and P0442, P0455) are common Ram codes: gas cap, EVAP hoses and the leak detection or vent parts near the tank.
P0456: causes, can I keep driving, and what to check first →
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0420 means the catalytic converter on bank 1 isn't cleaning the exhaust well enough, usually a worn converter, an exhaust leak or a lazy oxygen sensor.
On the Ram 1500: Catalyst efficiency, often with P0430: check for exhaust manifold leaks (broken manifold bolts are common on the Hemi) and misfires first.
P0420: causes, can I keep driving, and what to check first →
P0520 Engine Oil Pressure Sensor/Switch "A" Circuit
P0520 means the engine computer isn't getting a usable signal from the oil pressure sensor; check the oil level before assuming it's just the sensor.
On the Ram 1500: On the 3.6L Pentastar, the plastic oil filter housing is a well-known leak point, and the oil pressure sensor that sits in it often fails with it. Fix the leak at the same time or the new sensor gets soaked again. Confirm real oil pressure with a mechanical gauge.
P0520: causes, can I keep driving, and what to check first →
P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
P0128 means the engine isn't reaching normal operating temperature, almost always a thermostat stuck open.
On the Ram 1500: Thermostat codes are common on Hemis: a thermostat stuck open.
P0128: causes, can I keep driving, and what to check first →
P0171 System Too Lean (Bank 1)
P0171 means bank 1 is running lean (too much air or too little fuel), most often from a vacuum leak or a dirty MAF sensor.
On the Ram 1500: Lean codes: vacuum leaks or a dirty sensor; on the Hemi check the PCV hoses and intake.
P0171: causes, can I keep driving, and what to check first →
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Common codes and known problems as widely reported for these model years; your vehicle may differ. Check nhtsa.gov/recalls and ask a dealer about service bulletins for your VIN, and confirm in your service information.