Tip & How-To about Chevrolet 1500

Why is my car's CHECK ENGINE LAMP on?

Most vehicals manufactured after 1980 have some type of Check Engine Lamp. The lamp is a telltail signal initiated by the On Board Computer. The Computer recieves input signals from various sensors in the Fuel Management System. These inputs allow the On Board Computer to adjust it's Outputs to coinside with variables which may or not be within it's control. When the On Board Computer detects an input or output which contridicts normal known values, it turns on the Check Engine Lamp. The On Board Computer also sets (records) a fault code in it's memory, which should lead the repair technician to the proper area for diagnosis. Most vehicals with require a scan type tool to access the fault code. After the code is aquired diagnosis can begin.

Posted by on

Cars & Trucks Logo

Related Topics:

Related Questions:

1 Answer

the hazard back lights wont quit blinking when car is running even when i pull the fuse on a 2002 buick regal


What fuse are you pulling ?

Hazard Lamps
The hazard warning switch is part of the turn signal switch. The turn signal switch receives battery voltage at all times through the HAZARD SWITCH Fuse. When the hazard switch is placed in the HAZARD position, battery voltage is applied to the hazard lamp/turn signal lamp flasher. The hazard lamp/turn signal lamp flasher sends a turn signal flasher signal to the turn signal switch. The turn signal switch provides all of the turn lamps and turn indicators with the turn signal flasher signal, simultaneously flashing them on and off.

Turn Signal Lamps
The front turn signal lamps are made up of the front park/turn signal lamps and rear turn signal lamps. The front turn signal lamps flash with the rear turn signal lamps when a turn is initiated using the turn signal/multifunction lever. The turn signals will operate only with the ignition switch in the RUN position and will not operate during hazard flasher operation.
When the ignition is turned to the RUN position, battery voltage is supplied to the TURN SIGNAL Fuse. Battery voltage is then applied through the turn signal fuse circuit to the turn signal switch. When the turn signal switch is placed in the LH or RH position, voltage is supplied to the hazard lamp/turn signal lamp flasher. The hazard lamp/turn signal lamp flasher supplies a turn signal flasher signal to the turn signal switch. With the turn signal switch in the LH or RH position the corresponding turn signal indicator, rear turn signal, and front turn signal receive the turn signal switch signal and will flash. The front turn signals receive the turn signal switch signal from the turn signal switch via the BCM. The turn lamps are permanently grounded.

Replace the turn signal switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Feb 11, 2017 | Buick Cars & Trucks

1 Answer

car stalls after turn or idle


Q; Is your service engine lamp on? This vehical has a power steering pressure switch,witch helps your engine maintane idle at parking lot monuvers. its next to your power steering pump.you can check if it works by starting your engine and let it warm up. then without tuching your gas pedal turn your steering wheel slowly , the engine should maintane its idle. if this works and your service eng. soon is not on then try cleaning your throttle plate. A dirty throttle is alot of stalling causes with all vehicals.

Jan 18, 2012 | 2000 Ford Focus

1 Answer

my check engine light and a double end wrench symbol. what is this


MIL Lamp (wrench) --- Malfunction Indicator Lamp

They have been on all vehicles since 1980 some 31 years

OBD1 1980 thru 1995

OBD2 1986 thru 2011

(On Board Diagnostic System) Study that on internet
& read your owners manual

No Manual --Helm.Com

Now you check for codes,have the issues diagnosed &
then repaired

Three step process,thirty years now,nothing new

Jun 28, 2011 | 2007 Ford Edge SEL Plus

1 Answer

need to know the alternator power specs. my check engine light came on for about 2-4 minutes then shut off, and came back on for about a minute. it usually does after i haven't driven it for about a day or two. but recently it has been doing when i might have the stereo up too loud or on an album that has a lot of bass.


  1. The orange ( check engine lamp) is a telltail for the engine control computer.
  2. If the computer determines that there is a problem with an input or an output it sets a trouble code in the computer.
  3. To retrieve the code a scan tool must be used.
  4. Some parts houses offer to scan the codes for free
  5. When you get the code repost your problem with the code.
  6. Its possible (but not probable) that a monster audio system could over tax a charging system causing low voltage input to the computer and set a code
  7. Cavalier peak alt output should be at least 70 amps
  8. Hope this helps
  9. Let me know

Sep 07, 2010 | 1989 Chevrolet Cavalier

1 Answer

The pale orange engine light on the dashboard came on in my 2004 PT/Cruiser. I heard such things that even the catalytic converter may do this. What else could be the problem?


engine lamp is a telltail that something is wrong in the engine management system. Is the gas cap tight? if so certain parts houses will scan the failure code for free. obtain the code and repost your problem

Sep 06, 2010 | 2004 Chrysler PT Cruiser

Not finding what you are looking for?

1,554 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

75051 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7726 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Loading...