Engine coolant thermostat stuck open, so the engine runs too cool and exhaust heat is low; Faulty or inaccurate exhaust temperature sensor, or a coolant temperature sensor giving a wrong reading; Wiring or connector damage on the exhaust temperature sensor circuit, such as corrosion, chafing or heat damage; Fuel, ignition or air metering fault causing poor combustion and a failed catalyst warm-up strategy (for example misfires or a faulty airflow reading); Exhaust leak upstream of the temperature sensor, letting in cool air or skewing readings; Outdated or faulty engine control software calibration, where the manufacturer has issued an update for the warm-up strategy.

P050E

Cold Start Engine Exhaust Temperature Too Low.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
5: AreaVehicle speed, idle control and auxiliary inputs
0E: FaultThe specific fault in that area

What it means

P050E is the generic code for the engine exhaust temperature being too low during a cold start, when the control unit expects the engine to be running a catalyst warm-up strategy. The ECU compares the exhaust temperature, either measured by a sensor or modelled from engine data, against the target for the time since start-up. If the exhaust stays cooler than expected for too long, the code is set.

Symptoms

Engine warning light on
Slow or reluctant warm-up, with the heater taking longer to produce heat
Rough or unstable idle on a cold start
Poor fuel economy
Possible emissions test failure
Hesitation or reduced performance until the engine is warm

Possible causes

Engine coolant thermostat stuck open, so the engine runs too cool and exhaust heat is lowlikely
Faulty or inaccurate exhaust temperature sensor, or a coolant temperature sensor giving a wrong readinglikely
Wiring or connector damage on the exhaust temperature sensor circuit, such as corrosion, chafing or heat damagepossible
Fuel, ignition or air metering fault causing poor combustion and a failed catalyst warm-up strategy (for example misfires or a faulty airflow reading)possible
Exhaust leak upstream of the temperature sensor, letting in cool air or skewing readingspossible
Outdated or faulty engine control software calibration, where the manufacturer has issued an update for the warm-up strategyrare

How to diagnose

Read all stored and pending codes and freeze frame data, noting engine temperature, load and ambient conditions when the code set
Check for other related codes (misfire, coolant temperature, thermostat, sensor circuit) and deal with those first
Inspect the exhaust temperature sensor, its wiring and connector for damage, corrosion, water ingress or heat damage
Watch live data on a cold start: compare coolant temperature and exhaust temperature readings against the actual temperatures, and check how quickly the engine reaches operating temperature
Check the thermostat operation by monitoring the warm-up curve and feeling the hoses; the expected time to temperature depends on the model and engine
Check the coolant level and look for signs of an exhaust leak upstream of the sensor
Check fuel trims, misfire counters and airflow readings for signs of poor combustion
Check for any manufacturer service information or software updates relating to the warm-up strategy for the specific model and engine

How to fix

Replace a thermostat that is stuck open or opens too early, and refill and bleed the cooling system correctly
Replace a faulty exhaust temperature sensor or coolant temperature sensor
Repair damaged wiring or connectors in the sensor circuit
Fix the underlying combustion fault, such as ignition, fuelling or airflow issues, that is preventing normal warm-up
Repair any exhaust leak ahead of the sensor
Apply an updated manufacturer calibration only if one is available for this known issue

Can I keep driving?

Low severity

The car can normally be driven while you arrange a repair, but do not leave it for long as the underlying fault may harm fuel economy and emissions. If the engine is misfiring badly or running poorly, have it checked sooner.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.