How to Replace a Bad Computer in Your Car

How to Replace a Bad Computer in Your Car

one, two, three, four! Rev up your engines! It’s time for the Scotty Kilmer Channel today I’m going to show you how to
change a bad computer on a car, now this Lexus is smoking like mad
because the fuel injection system is all off and it’s dumping raw gas into the
engine, now I scanned the vehicle and it came up
with this code P0605, which says that the main computer has a problem with its
RAM memory, now many times it’s hard to diagnose a bad computer in a car, but in
this case, it’s got a bad computer code and in a Lexus that almost always means
the computers gone bad now in this Lexus, the computer is behind the
glovebox, so we have to take that out there’s just five little screws and
bolts that come off and then the whole glovebox just slides out of the way, and
we go inside, here’s the main computer, right hear, but before we start messing with
the computer first, take off the negative battery terminal, so there’s no power
going in, so you don’t fry any computer parts, then we just unplug all the
electrical connections, they just have clips that snap off, you squeeze them one
at a time, and out they come, then you a wrench and unbolt the little ten millimeter bolts that hold the computer into the body, and move the wires out of the way, and out comes the
computer, now you’ve noticed me wearing gloves before, and that’s to keep my hands clean, but
in this case it’s your something else, it’s to keep static electricity from
ruining any computer parts, when we put the new computer in, and speaking of new
computers, I’m taking a gamble on this car, because the new Lexus computer costs
$2,300, I’m going to get a used one from a salvage yard and if you do that, you got
to make sure these numbers match, especially these last, ones 50303, there’s various different computers, you want the same number,
so now after a trip to the junkyard, we’ll put this used computer in, first we take
the computer and slide it back into place and bolt it back in, we just bolt it
back into place and then snap all the electrical connections back in their
holes, then we’ll reconnect the battery make sure that’s on tight, then we’ll
cross our fingers and turn the key and the smokes gone it’s not pouring out
of the exhaust anymore, so now we can put the glovebox back in, then just finish by
tightening all the screws up that hold the glovebox in place, and then we’re
done, so the next time your car’s computer crapped out on you, why not fix
it yourself, and remember if you got any car questions just visit the Scotty
Kilmer channel and I’ll answer them as soon as I’m done drinking some of this

About the Author: Michael Flood


  1. Hi Scotty, thank you for passing on the knowledge. Would a 2001 ES300 be considered old enough to not need reprogramming or will I have to reprogram this one? If so, what does it cost to reprogram one? Are dealers the only ones that do this?

  2. waddup scotty.. that pt cruiser issue I had, well I've narrowed it down to where the engine compartment gets to hot to even touch anything under the hood when it just dies,(which is usually from a stop) but the temperature gauge shows its fine.. it just turns over n over and wont start… after a few hours , I disconnect the pcm and battery +  then re connect it and it'll start again… it does this every trip away from home.. but gives no error codes.. and the new cooling fan is running when it quits.. bad pcm ? catalytic converter? fan not running on high ?.. any guess's ?

  3. Really, just go the a junk yard and swap it? What about the security system for the immobilizer and VIN?

  4. 2007 toyota corolla running code p0741 suggested part is replace the ECM does that sound right or could it be something else?

  5. 2003 alero: engine shuts off randomly while either driving or at idle. rpm will surge/sputter, sometimes before engine shutting off, gas gauge will indicate there is no gas when there is clearly gas in the car. No one can tell why, just…"oh it sounds like an electrical problem"…. the only code that will pull is my ABS sensor, which that light has been on for some time. ive had my fuel pump looked at, they said it was fine. is it my computer?

  6. Hey I have a 2004 chrysler crossfire can I put in a used pcm. Or do I have to buy a new on please help thanks

  7. Hello there Scotty, I am a follow of yours and really enjoy everything that you taught us throughout the years. My question for you is I have a 2006 Grand Jeep Cherokee and I believe the PCM has a short in it I'm going to swap it out with one with the same numbers but my question is do with that need to be reprogram?

  8. I'm having the same issues with my 96 lexus 400.. Ive change coils plugs sparks. Etc.. And spent $700.00.. Come to find out it its the ecu.. Wondering if its really that simple of swapping out the ecu..

  9. Hi I have Lexus 220d 2006 p1100 error how do you recommend me to remove this code I couldn't find any video on YouTube
    Where the ECM of car is located ?
    I have already cleaned the dirty maf sensor

  10. Scotty, I have a 05 Honda Accord. Hurricane Harvey decided to flood the car up too the center cap on the wheel's. 1. fried computer 2. replaced computer with a USED ONE. 3. had to have a locksmith come and reprogram the key. 4. now the car will start but run's rough and engine light came on. 5. plugged OBD into the car and has o2 sensor not communicating. 6. bought a new ( oh! Bank 2 sensor 1 downflow)sensor and the car still will start and die. 7. check engine light back on and same codes random misfire and o2 sensor not reading. 8. please help I cant afford a shop bill rt now so if you can point me in the right direction any help in this manner will be much appreciated. Don from Webster Texas

  11. Hey Scott I have Infiniti G35 code sayP0603 – Internal Control Module Keep Alive Memory Error
    if replace ECM or PCM do i need to reprogram those computer? thank you

  12. I have a bad ecu on my accord can u plz tell which number should I match for perfct fit on when i buy another one. Thnxx

  13. Things I used in this video:
    1. Actron Scan Tool:
    2. Disposable Gloves:
    3. Ratchet and socket set:
    4. Mechanic’s Tool Set:
    5. Common Sense
    6. Full HD Camera:
    7. My computer for editing / uploading:
    8. Video editing software:
    9. Thumbnail software:

    🛠Check out my Garage to see what I use every day and highly recommend:

    ❗️Check out the Scotty store:

    👉Follow me on Instagram for the latest news, funnies, and exclusive info / pics:

  14. scotty i have 04 sebring and the computer is bad, i got 1 from the junk yard , so will it need to be programmed or anything, or just plug it in and keep my fingers crossed???

  15. Hey Scotty, im about to look for a computer for mi honda accord 96,on a junk yard any suggestions what numbers i need to look for to match, 37820-POB-A70881-218080 those are the # on mi car

  16. Why Scottie Kilmer so articulate and delivers very briefly that even a Slow learners and Retards could understand him???..He's just the Best Mechanic Teacher out there ever.

  17. SCOTTY – I bought a 2002 TOYOTA AVALON from a private party – didn't realize I was only using a valet key, rather than original until key started getting stuck in the ignition. Then nothing.. locked up.. took it to dealership & they were able to make 1 key as the computer wouldn't program correctly; said I needed a new computer costing $1500 + – then gave me a part number & suggested I get it on line. According to what I'm reading, this computer cannot be programmed by a dealer.. what do you know? Thanks, Sherri

  18. Hey Scotty I have a 2016 GMC SIERRA 1500
    P/UP believe it or not they took the computer an old one for the junk yard will work?

  19. Scotty I have a 94 Corvette that the engine turns of randomly while driving. You usually got to wait a couple min to restart car and sometimes it won't go over. Is this a bad computer or wire harness. I replaced the Fuel Pump, Opti Spark and radiator. Basically did everything else to the car.

  20. Dear sir can explain me aoto electrician computer I am aoto elelectrician computer I don't know so please help me wait your answer

  21. Hello Scotty Hope you can help i have a 2002 Nissan Altima With A Alarm On It My Car Was Envolved In An Accident And I fixed It After I Fixed I Started Having Problems Of It Not Starting I Took It To This Mechanic He Told Me It Was All This Sorts Of Things And It Will Work For A While And Do The Same Thing Again He Ended Up Stealing My New Battery And Putting An Old One I Just Wanna Know Whats Wrong With It I Hope You Can Help The Thinks I Put In Where New Fuel Pump New Camshaft And Crankshaft Sensors New Battery And In The End He Said He Replaced The Computer It Will Run Good And Turn On For About Two Weeks And Then It Wont Start Suddenly I Unplug Both Battery Cables And Leave It Like That For Two Days And It Will Start Good Again For About Two Weeks And Then It Wont Start All Over Again Till I Repeat The Battery Process All Over

  22. How to know when someone swapping out the computer 2002 GMC envoy can they use my computer on a 2003 GMC ,? Does it have numbers to match my truck so I can show where it's been swapped out?

  23. Ok so I went to a mechanic to see what was wrong with my Nissan Maxima and he told me to buy a new computer so I did and still didn't start so I wanna take it to a dealership and see what's wrong do I need to reprogram the new computer or can I just install it sorry I know nothing about cars

  24. What are the odds of finding a same computer that work in a junk yard? (Especially one that works)
    Here the dealer has first pick.

  25. Hello Scott I want to know well is that computer of Infiniti FX35 2010 because I try to repeat by my self if you can help me
    Thank you

  26. I have the same exact car. I'm currently working on fixing it myself. At first I had random misfires. I believe that was caused by a broken distributor cap, which allowed electrical current to arc to the block. I replaced that and stopped the arc. Im still having issues. Is it possible to have a bad computer when you don't have a code for that item… I've been killing myself for months trying to figure this out… BTW this is the first car I've ever worked on. Please help

  27. My truck turned off on me when I was going home I thought the fuel pump was no good because I turn the key for off and on with the fuel filter off no fuel came out so I change the relay still nothing fix the problem I also put starting fluid in the throttle body and still did not start do you think I have a bad computer

  28. I've been reading online about replacing my Lexus ES300 ECU. I went to the Pick-N-Pull location, and their computer showed that I can use the ECU from a 95 to 98 Lexus ES300 or a Camry of the same years. Is it even possible to do that? The worker don't know either. Should I trust their computer's suggestion? I also want to pull the ABS controller. Please help/suggest!!

  29. I swap the computer on my CTS but it's still acting the same check engine light came on. Do I need to unplug the battery to reset the computer?

  30. Hey would it be the same plug and play with a 03 eclipse spyder gs? Or would it require a lock Smith to reprogram to key (it's a basic key no chip) thanks

  31. Hi, How about Holden Cruze 2009 ECU replacement? Does it need reprogramming too? What else needs replacing with ECU?

  32. scotty, please help. i was having startup problems. i replaced the ignition switch a few months ago, seemed to work. then more problems. a shop said the ignition switch was loose and resetting or locking the computer and that he superglued it. anyway it would start after that. now no start, it cranks. error codes are different but all suggest bcm. i don't know if its that or the crankshaft sensor or if its the same problem with the ignition switch as before. its a 2002 alero gls. i have also replaced the fuel filter, 3 ignition coils, ignition control module. i think all of those parts were fine tho and it was just the ignition switch. is it bcm or ignition switch.. and what does it mean the ignition switch is loose and resets or locks the computer? any help would be greatly appreciated. i'm at a loss.

  33. hi Scotty I have a question about swapping the computer in my 06 Ford E350. I don't have a key immobilizer and was wondering how I can go about swapping the computer without getting it programmed. thank you very much and I love your videos

  34. Hi Scotty. Thanks for this video. I have a question: In this video, you did not reprogram the immobilizer. Whereas in another video you had to reprogram the immobilizer. Why?

  35. Hey Scotty so I have a 03 Ford F-150 v8 xlt triton and it rain a water leaked through the windshield and touched the electrical wires and now my truck won’t start it just cranks any ideas?? Would the computer need to be replaced??

  36. If i swap the computer on my 2005 nissan altima 2.5 with another 2005 nissan altima 2.5 do i have to get it reprogrammed

  37. I have an 04 Nissan Quest. The ECM in this vehicle is damaged beyond repair due to the well known problem of water damage due to it's location mounting. Is this ECM changeable from another vehicle as you did in your video? Thank You

  38. Hey Scotty I had a bad tranny in a Lexus is250 2007 and it was the shift solenoids in the obd2 scanner and when I changed the tranny now it won’t even engage in drive or reverse it clicks and everything but just revs and won’t move and now I’m getting faulty shift solenoid do you think both Trannny’s are bad or it might be ecu or something with the car ?

  39. I have a 99 honda civic ex. I changed my knock sensor and its still coming up he said it might be the computer just got it wanna know if i have to re program it first ty so much

  40. Hey Scotty , I replaced my computer on my 2007 Honda CR-V and the car starts and shuts off ? The green key light is blinking ? Does it mean I have to get it programmed ? Thanks

  41. Hi Scotty, my 2014 Hyundai sonata starts good but has been on limp mode and all guages donf move, abs , traction control and engine lights are on. Even Hyundai dealership cant communicate with the system with a scan tool. What would be the possible reason?

  42. My car won't start, but every other part related to the ignition is good. Battery, fuel pump, starter, and alternator. I have code p0401, I failed the smog test. I'm about to replace the EGR valve and the vacuum hose. What are your thoughts on this?

  43. Hey Scotty. I have a Honda Pilot 2004 that cranks but no start. I just replaced the fuel pump, Ignition coils, spark plugs and is not coming on. In a year I did a Timing Belt, Serpentine belt, Waterpump, New Battery. I inspect the Fuel Pressure Regulator and the air hose doesn't have gas, so it should be fine. Bad injectors?. Bad ECU?. I Suspect is the ECU because something the car was running slow when it was cold and had to crank the car like three times to come on when the car was hot. When car was cold, it comes on quick. Now Cold or hot is not coming on. Also no check engine codes on. Any tips missing?.

  44. I'd just get a couple of the same RAM chips and solder in some new RAM chips. Just gotta make sure they're the same type and hope the company is still in business and making them.

  45. Question Scotty, I Have a 2005 Toyota matrix, would I have to reprogram the computer as well or no need for that on a matrix?

  46. Hi scotty..

    For a 2012 Nissan Altima 2.5 ECM or TCM replacement… is there any reprogramming required if used computers are the ones replacing the original if both have same serial numbers?

  47. Most mechanics gloves these days are conductive to allow usage if touchscreen scanners and cellphones. So they won't prevent you from insulating against static. Pull out a spark plug wire and touch it while the engine is running. It'll electrocute you through the glove.

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