Why does the engine management light come on first?
b) If the engine management light comes on first, followed by the DPF light, it indicates an issue within the DPF system, for example temperature, pressure, sensors etc. Use the EEC DPF tool to identify this. 1. Check pressure sensors as there could be a build up of water; 2. Examine pressure pipes for damage.
What should the control module voltage show on a car?
Control Module Voltage — Power input to the control module. Normally, this should show battery voltage minus any voltage drop between the battery and the control module (which should be less than a few tenths of a volt). Distance Since DTCs Cleared — How many miles the vehicle has been driven since any DTCs were cleared with a scan tool.
What are the symptoms of a bad ECM power relay?
A bad relay may cause the vehicle to crank, but not start, or sometimes not even crank at all. 3. Battery drain or dead battery. A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off.
Can a bad mass air flow sensor trigger a check engine light?
Bad mass air flow sensor with no check engine light? Sometimes a mass airflow sensor can start to fail and even trigger engine error codes such as P0101 and P0102, without triggering a check engine light. There must be a problem with the mass airflow sensor circuit for the check engine light to illuminate.
Can a car go into reduced power mode with no codes?
Thoughts? Running a scan tool and watching the parameters while the engine is running would be the first thing I would do with no codes stored. This is a rare instance that no codes are displayed yet the engine goes into reduced power mode.
What does the engine management warning light mean?
The engine management warning light is different from the other lights on your dashboard, as it doesn’t alert you to a specific fault. Unlike the coolant temperature warning or low oil level warning lights, the engine management light (EML) can be triggered for a number of reasons.
Do you need an engine warning light to pass Mot?
The answer to this is ‘no’ – the light itself isn’t but the issue that causes could prevent your car passing its MoT depending on what it is. Unlike many of a dashboard’s other warning lights, an engine warning light doesn’t alert you to a specific fault.
What to do if check engine light is on but no code?
Check the make and model of your reader to see what it is built for and if all else fails, head into a parts store and they should be able to read the issue at no cost to you. No code being generated on the reader does not mean the driver is in the clear.