Any time a check engine light comes on, the onboard computer (EMC/PCM) sees an error with the engine or running gear.
This includes when there is a flashing check engine light that then stops.
Why Would a Check Engine Light be Flashing and Then Stop?
A check engine light will come on when then the onboard computer (EMC/PCM) detects an error in the engine, running gear, or transmission.
When the error clears, the engine light goes off.
Even if the engine light stays off, there may be an issue, and the cause should be found as it may return.
What to Do When Flashing Check Engine Light Then Stops
- Check the Engine Oil
- Watch for Engine Overheating
- Scan for Error Codes
The first thing to do is check the engine oil and be sure it is not low.
While many things can cause the engine light to come on, it is best to first check for things that can cause engine damage.
If the engine oil is low, it can cause damage to the engine.
The engine dipstick will have a low-level maker that the oil must be over, or the engine could be damaged.
An overheating engine can crack the block or blow a head gasket causing a lot of damage.
Watch the temperature gauge and be sure the engine is not overheating, as this can cause more problems.
If the engine is overheating, it is best to pull over, wait for the engine to cool, and check the coolant level.
Many things can cause the engine light to come on and go off.
There is only one way to know for sure what the problem is, and that is to scan the onboard computer (ECM/PCM) for OBDII codes.
This is easy to do with many low-cost OBDII scan tools available, some less than $25-$30 dollars.
Many automotive stores will often scan the codes for free.
Be sure to call around first, but in my local area, Auto-zone is known to scan codes for free.
Once a code is known, it will point to what the issue is.
For example, a P0101 error code would give a “Mass or Volume Air Flow “A” Circuit Range/performance:
In this example, there is an issue with the MAF sensor, which usually just needs to be cleaned.
There may also be more serious issues, but the only way to know for sure what is causing the engine light to come on is to scan for OBDII error codes.
Possible Causes When Flashing Check Engine Light that Then Stops
- Low Engine Oil
- Engine Overheating
- Misfire or Spark-Related Issue
- Fuel Delivery Problem
- Emissions Problem
Many things can cause the check engine to flash and then go off and return.
The main method to find the problem is to scan for OBDII error codes.
All vehicles manufactured after 1996 have an OBDII port located under the driver-side dashboard.
A scan tool can be plugged into the port and will read any errors that the engine may be having.
It is quick and easy to do and will point to what the problem is.
If you can not get a scan tool, be sure to check for the things that can cause engine damage.
The main things that can cause engine damage is low oil and overheating.
While other issues may leave you stranded, low oil and overheating can cause serious problems.