Check Engine Light

The engine computer has detected a malfunction and set a code.

For my 1996 E320 I disconnected the battery for approximately 2-3 minutes. It worked. My wife had just recently filled the gas tank with bad gas that caused it too misfire.

The OBDII system in your vehicle has several sensors that monitor conditions and "report" to the system's computer. When a sensor senses a malfunction, a signal is sent to the computer and the Check Engine light will illuminate. To find the malfunction you have to have the sytem scanned by an OBDII scanner tool for the trouble code(s). AutoZone and similar auto supply stores offer free scans.

Most connectors are located under the drivers side dash. Most are connected to the bottom side of dash.

Just disconnect a battery cable for a couple of minutes.

The Alternator is not putting out enough voltage. If you recently replaced the alternator with a "new" remanufactured alternator that one could be bad to your truck somewhere to get it tested.

The check engine light is all because of the ECU has detected a problem with the emissions system. Have the ECU scanned with an OBD2 scan tool. This will retrieve the code that has been set by the computer. This code will tell you what part is being effected but not necessarily the defective part.

With a scan tool, or if you don't have one, see the FAQ in the "related links", question number 12.

Check with a professional. Expect them to charge between $50 and $80 to find out what caused it. Don't just turn it off.. it'll come back soon.

Had the samr issue ad it was an injecor.. Had the samr issue ad it was an injecor..

Check your engine. Check your fluid levels and add if needed.

You will need to plug into the car's OBD II connector and scan vehicle's computer for codes.

Now, repair the problem that caused the light to come on, then clear the computer system.

If the repair is successful, the light will stay off. Otherwise, it will come back on again after some driving interval.

You can buy cheap code readers on eBay - they will give you the codes and reset the computer (turning off the check engine light). You can take the code and look it up on the internet to see what it means and find help for fixing problems. If the problem is not fixed, the light will come back on.

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Also, you could: "disconnect the negative battery connection. Press your brake pedal down for 10 seconds. Reattach your negative battery connection. The computer will be reset." It worked for me. After changing my spark plugs my check engine light was still on, then after doing this my check engine light went off.

TAke it to the dealer. They have check out charts for times when the computer doesn't set codes.

In vehicles with an electronically controlled transmission, the computer will trip the "Check Engine" light when it detects a problem with the A/T. You have a transmission problem. Also, if the computer senses a serious problem with one of the main sensors, it may go into "Limp Home" mode where it uses calculated defaults instead of input from the sensors to control the engine. Check for trouble codes. On a 1999 LHS, with the car in off and in Park, turn the key on, off, on, off, and then on. Look at the odometer, the trouble codes should display there. Write them down then look them up on the net with a search engine or shop manual if you have one.

Try disconnecting the battery for about 10 minutes to reset the code Went to Autozone to see if I replaced the wrong part. They said I had to wait "a while" till the change was recognized. That the computer used some type of formula of engine starts, miles, and gears shifted through before it would turn it off. It has been 3 days, about 8-12 engine starts and about 30 miles.

I have a 1995 Pontiac Sunfire . The "check gages " light comes on when my gas tank is on empty. I dont know if this is a right answer but this is how I know I need to fill up at the gasbar .

Out of the visible colors, red.

The lower the wavelength the less it is dispersed.

Disconnect the negative battery cable for 5 minutes. Note that the light will just come back on unless you repair the problem.

This code indicates a 'small leak in evap system' . - Simplest and cheapest solution is usually fitting a new gas cap. If that doesn't do it look for a loose or broken small vacuum pipe in the engine bay. Also possible that evap canister is faulty.

As you don't give type and year of vehicle its very difficult to diagnose further.

The P0410 code refers to the emissions system. The AIR pump puts air to the exhaust to lower emissions. It takes in outside air and pumps it through two one-way check valves into each bank of the exhaust.

About 90% of the time that this code is set, the one-way check valves have worn out or failed and allowed water (which occurs naturally in the exhaust) back into the pump. In any cold climate, especially in climates with higher humidity, this water may be more excessive. The water partially fills the AIR pump, it can then freeze. When the PCM commands the pump on, if the pump is frozen it cannot turn, thus overloading the circuit and "popping" the fuse. Check the fuse first.

according to the manual:

you have to have the engine off... turn the key to the "ACC" position which is the knotch that allows power but doesn't turn the engine... then press the gas pedal fully THREE times within FIVE seconds...

however it doesn't always seem to work

This is incorrect and will not work.

1. Turn the key to the "ACC" position which is the notch that allows power but doesn't turn the engine.

2. The display will read change engine oil soon - hit the display button(i) and the display will read 0% oil life.

3. Hit reset button (the check mark button) for 5 seconds and the display will change to 100 % oil life.

4. It may not work the 1st,2nd,3rd .... attempt , but will work eventually.

To Fix:

go to the oil indicator by pressing the second button. Hold on the tick mark button for 3 seconds. This will reset the remaining percentage to 100%.

Have vehicle scanned to determine the problem

Would seem that of the four heater plugs fitted to this engine one or more have failed. They are located in the cylinder head and are joined by a single wire . they cost between £6 and £12 each dependant on engine . hope this helps

if your take it to a autozone tell them you have a check engine light and they will tell you whats wrong if anything and reset it take it to autozone and tell them your check engine light is on and they should reset it

Trouble code P0421 means: Catalyst Efficiency Below Normal (Bank 1)