P20E8 on Peugeot
Reductant Pressure Too Low
P20E8 on Peugeot vehicles indicates reductant pressure too low. Au7o has documented this code across 1 Peugeot model — most commonly on 208. P20E8 is a generic powertrain code that applies to diesel vehicles with a Selective Catalytic Reduction (SCR) emissions system, which injects diesel exhaust fluid (DEF, also sold as AdBlue) into the exhaust to convert smog-forming nitrogen oxides into harmless nitrogen and water. The engine control module sets this code when the DEF pump cannot build or hold the pressure the system needs (roughly 70-90 psi on most applications) to dose fluid accurately into the exhaust stream. Day to day you may notice little beyond a check engine light and a DEF or SCR warning message, though some vehicles show reduced power. Because SCR operation is emissions-mandated, ignoring the code typically starts a countdown to a derate: the vehicle will progressively limit speed (often to 55 mph, then as low as 5 mph on trucks) or refuse to restart until the fault is repaired. Some manufacturers word the same code as "DEF Pressure Too Low" or "SCR Urea Pressure Too Low," but the meaning is identical. Typical repair costs on Peugeot range from $350 to $1,800, depending on the specific model and root cause.
Common Causes of P20E8
- •Failed or weak DEF (reductant) pump that cannot build specified pressure
- •Clogged reductant pump filter cartridge — DEF crystals gumming the internal filter is the most common cause on Duramax and Power Stroke trucks
- •Contaminated, diluted, or crystallized DEF fluid (or DEF frozen in cold weather due to a failed heater)
- •Leaking DEF supply lines or fittings, or a DEF injector stuck open and bleeding off pressure
- •Faulty reductant pressure sensor giving a false low reading
- •Damaged or corroded wiring/connectors to the DEF pump or pressure sensor
- •Low DEF tank level
P20E8 on Peugeot by Model
Peugeot 208(1 issue)
- AdBlue/SCR System Failure on BlueHDi Diesels — Urea Fault With Start-Prevention Countdown2015-2023
BlueHDi diesel 208s suffer chronic AdBlue (SCR) system failures: the urea injection pump and its control electronics are integrated into the AdBlue tank, and pump seizure, urea crystallisation, faulty level sensors and (on pre-2018 cars) a non-vented filler cap that pulls a vacuum in the tank all kill urea delivery. The ECU then logs faults such as P20E8 (reductant pressure too low) or P20EE, lights the UREA/engine warning and starts a countdown (typically 1,100 km) after which the engine is prevented from starting. Peugeot's official fix is a complete new AdBlue tank assembly with ECU coding, quoted around GBP 1,100-1,300 at UK dealers.
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View P20E8 across all makes →Frequently Asked Questions
What does P20E8 mean on Peugeot?▼
P20E8 stands for "Reductant Pressure Too Low." P20E8 is a generic powertrain code that applies to diesel vehicles with a Selective Catalytic Reduction (SCR) emissions system, which injects diesel exhaust fluid (DEF, also sold as AdBlue) into the exhaust to convert smog-forming nitrogen oxides into harmless nitrogen and water. The engine control module sets this code when the DEF pump cannot build or hold the pressure the system needs (roughly 70-90 psi on most applications) to dose fluid accurately into the exhaust stream. Day to day you may notice little beyond a check engine light and a DEF or SCR warning message, though some vehicles show reduced power. Because SCR operation is emissions-mandated, ignoring the code typically starts a countdown to a derate: the vehicle will progressively limit speed (often to 55 mph, then as low as 5 mph on trucks) or refuse to restart until the fault is repaired. Some manufacturers word the same code as "DEF Pressure Too Low" or "SCR Urea Pressure Too Low," but the meaning is identical. On Peugeot specifically, this code is documented across 1 model.
What causes P20E8 on Peugeot vehicles?▼
Common causes on Peugeot: Failed or weak DEF (reductant) pump that cannot build specified pressure, Clogged reductant pump filter cartridge — DEF crystals gumming the internal filter is the most common cause on Duramax and Power Stroke trucks, Contaminated, diluted, or crystallized DEF fluid (or DEF frozen in cold weather due to a failed heater), Leaking DEF supply lines or fittings, or a DEF injector stuck open and bleeding off pressure, Faulty reductant pressure sensor giving a false low reading. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P20E8 on a Peugeot?▼
Repair costs on Peugeot range from $350 to $1,800, depending on the specific model and root cause.
Which Peugeot models have P20E8 documented?▼
Au7o has documented P20E8 on 1 Peugeot model: 208.