# Engine cuts off then back on **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [January 16, 2019, 10:41am UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740 "2019-01-16T10:41:51Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![George\_McConnaughy](https://avatars.discourse-cdn.com/v4/letter/g/54ee81/32.png) [@George\_McConnaughy](https://community.cartalk.com/u/George_McConnaughy)\ **Post date:** [January 16, 2019, 10:41am UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/1 "2019-01-16T10:41:51Z")
Hyundai elantra 2003, engine will cut off when driving but will come back on. It is almost like turning a light switch on and off. It will run fine for days then it starts cutting off and on. When it is cold it seems worse. I have cleaned the battery terminals . It seemed fine for a few days then started again. ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [January 16, 2019, 12:13pm UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/2 "2019-01-16T12:13:31Z")
What else happens when the engine cuts off. Dash warning lights come on? Radio cuts off? Symptoms seem like an brief electrical failure, but where? Ignition switch maybe. ---
**Author:** ![George\_McConnaughy](https://avatars.discourse-cdn.com/v4/letter/g/54ee81/32.png) [@George\_McConnaughy](https://community.cartalk.com/u/George_McConnaughy)\ **Post date:** [January 17, 2019, 1:22pm UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/3 "2019-01-17T13:22:35Z")
The check engine light is on due to code for catylitic converter needing attention. The headlights, dash illumination lights. radio all stay on. Rpm meter drops, engine check light itself goes out and in a few seconds everything back to normal running. Gets 30 mpg. Sometimes I can drive a hundred miles with no problem, then it starts doing it again. It acts just like flipping light switch on and off repeatedly. Get the new AOL app: [mail.mobile.aol.com](http://mail.mobile.aol.com) ---
**Author:** ![COROLLAGUY1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/corollaguy1/32/7575_2.png) [@COROLLAGUY1](https://community.cartalk.com/u/COROLLAGUY1)\ **Post date:** [January 17, 2019, 2:53pm UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/4 "2019-01-17T14:53:34Z")
> [@George\_McConnaughy](#): > > It acts just like flipping light switch on and off repeatedly. Could be mistaken for an engine miss. Check spark plugs cables for signs of insulation damage.Spray water on the cables while the engine is running,you might see sparks or arcing if you look carefully.Do this test at night because it is easier to see sparks. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [January 17, 2019, 9:45pm UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/5 "2019-01-17T21:45:14Z")
> [@George\_McConnaughy](#): > > Rpm meter drops That could mean that the crankshaft position sensor is failing intermittently. > **[2003 HYUNDAI ELANTRA 2.0L L4 Crankshaft Position Sensor | RockAuto](https://www.rockauto.com/en/catalog/hyundai,2003,elantra,2.0l+l4,1415809,ignition,crankshaft+position+sensor,7196)** > > RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog. If the computer loses the signal from this sensor for even a second, the engine will cut off. Tester ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [January 18, 2019, 4:22am UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/6 "2019-01-18T04:22:45Z")
Failing fuel pump is another idea. My old VW Rabbit would sometimes quit running on the freeway. I’d pull over, wait 15 minutes, then it would start up and run as normal. That was caused it turned out by the fuel pump stopping b/c of a corroded/burned connection in the wiring from the pump to the fuel pump relay. ---
**Author:** ![donnaeastman](https://avatars.discourse-cdn.com/v4/letter/d/e0b2c6/32.png) [@donnaeastman](https://community.cartalk.com/u/donnaeastman)\ **Post date:** [January 18, 2019, 9:37am UTC](https://community.cartalk.com/t/engine-cuts-off-then-back-on/132740/7 "2019-01-18T09:37:48Z")
Check the alternator and make sure that the wiring it connected tight. Check the battery cables and make sure that they are tight and clean. Look for any loose ground wires to the chassis on the vehicle. If everything checks out to be working correctly, then the PCM may need to be replaced as it may have a battery disconnect condition. For further assistance or problem is unsolved go to a mechanic or a professional to have it diagnosed.