Sedens

Hi,
I need your help!! I drive a 2002 Honda CiviC EX with about 167,000 miles. About 4 days ago my battery light came on, I went to Auto Zone, they tested the battery and said it was the alternator. Before I could get it to the mechanic, I was driving around 30mph and all the sudden the rpm gauge and the temp gauge stopped working and the check eng light came on. As I pressed the gas, it wasn't really accelerating the way it should. Like it wasn't getting enough power. The mechanic changes the alternator(turned one of the bolts holding it, broke) and as I'm driving it home the same feeling. I stopped by Auto Zone and Advanced and the diagnostic tool could not get a connection to give me an error code. When I turn the key the car starts but unless I push the gas for about 20-30 sec it cuts off. Also, as I push the gas, the check engine light flashes and I hear a clicking noise. The car won't go over 60 mph. I took it to another mechanic and he could not get a diagnostic reading but said a fuse was blown, thinking that would fix it. That was changed and still the same problem. He then said it was the computer that needed to be replaced and I'd probably have to take it to the dealership. Overall, it feels like it just isn't getting enough power or a bad connection. Any help would be great.

Thanks,
Stephanie

anibis

The car is in limp mode, a flashing check engine light is never good. It could be a number of things, really need to get a code.

Why couldn't they get a code exactly? No way to connect their diagnostic or there was just no code?

Was there a CEL before you had the alternator changed?

lazlong

Where's the clicking coming from? You need to track it down. If it's not the engine then it's probably the main relay behind the glovebox. I've heard of people screwing up the ECM/PCM with low voltage, have it diagnosed for a bad ECM/PCM.

* DO NOT drive with a flashing engine light, you're causing major engine damage.

gearbox

iTrader: (95)

the alternator is tricky on these cars and if not properly grounded, it can fry the ecu. i have no way of knowing if this happened when the bolt broke or when the shop swapped it out. both could have caused it. but since you say the car was driving poorly before it was replaced, i have a feeling the damage was already done. the car can drive for a limited time on just the battery, like 50 miles maybe before it goes dead. how long did you drive after the battery light came on? if it does turn out to be the ecu, just grab a used oneoff ebay for $100 and have the dealer reprogram your key to match it. just be sure to find the specific ecu for a 2002 ex and trans type (auto or manual).

lazlong

Don't forget side airbags or not.

Sedens

To answer some of the questions, I only drove it with the battery light on home to the shop, which was about 25 miles. The clicking IS coming from behind the glovebox and stops after about 30 seconds. I'm not sure exactly why they were unable to get a reading.

lazlong

Yeah, sounds like a bad relay. Test those relays behind the glovebox.

gearbox

iTrader: (95)

did you get a new battery after the alternator install? cause the old one was prolly trashed after driving with a broken alternator. is the clicking happening only when you start the car or while driving?

Sedens

No, I didn't replace the battery. I had it tested after the alternator was replaced and it checked out good other than seemingly being overcharged. It is only clicking right after it starts for about 30 seconds as I press the gas. Then it seems to regulate itself and stops the clicking.

gearbox

iTrader: (95)

ah okay, maybe the relays were damaged. i would try replacing those first. if the battery was overcharged, its possible the alt was putting out more than the normal 14.4v which can also cause issues.

hondarider102

iTrader: (1)

Im having the same exact issue, changed my ground cables, how exactly would i test the relays? they make the same clicking sound,

also SEDENS did you find a solution?

gearbox

iTrader: (95)

if the relays make a constant clicking, they are usually bad or not getting enough power.

hondacivic02

i was just wondering what was the solution to your problem .....did you end up replacing the computer?


The same exact thing just happened to my car including the alternator bolt breaking except my car doesn't show battery light (it might have done it though) only check engine light .. and rpm gauge and temperature gauge will only work sometimes ...when i turn it on it will suddenly loose power and click and and when it clicks it flashes the check engine light and shuts off or almost shuts off if i accelerate it helps it stay on ..basically my car is going into what ive heard described as limp mode. the general mechanic says its my computer/ecu but the two dealerships ive spoken with said that's not likely.

karpet

Does it do something like this:[youtube]http://www.youtube.com/watch?v=8II0U8iVd40&feature=g-upl&context=G29eb8e5AUAAAAAAAAAA[/youtube]
This is my cars issue.

I think the computer is dead.

gearbox

iTrader: (95)

plug an obdII code reader in and see if it connects to your car. if it says connection failure, the ecu is likely bad.

ezone

FIRST you need to fix the alternator, then see if it still acts bad.
The loose alt causes unusually high system voltage, which makes the PCM go haywire. The gauge cluster relies on data that comes from the PCM, so it goes nuts too.

I can't hotlink the actual document, but here is a good copy:
http://www.enginebuildermag.com/Arti...tor_bolts.aspx


IF tightening/fixing the bolts doesn't solve all of the problems, you will probably need a PCM, and it needs to be programmed for the immobilizer keys.
And fix the alternator problem before it fries another PCM.

HTH

karpet

The alternator is fixed and working. I installed it per Honda guide lines, which is were I failed in the first place. If it installed like an old Chevy alternator it will fail.

My interest lies in which part to swap. Is the PCM bad or is the module that powers it dodgy? The PCM probably controls the power module so it might be the PCM that is killing it's own power.

Thoughts?

ezone

You aren't going to swap a PCM and have it work easily. It has to be programmed.
That means a dealer, (or a real heavily tooled lock shop or heavily tooled independent shop).

I'd drive to the dealer on the old PCM, swap to the new one in the parking lot, then have them program it. Save yourself a tow bill anyway. (This is how it works easiest in my mind. I have no idea how friendly your local dealer is about this. Call them ahead of time and ask.)
TAKE ALL OF YOUR KEYS WHEN YOU DO THIS!!!

HTH

MPTShadowz

Was it your computer? Having same issue.

anibis

If your alternator bolt came loose/broke it'll fry your computer.

If you try to connect a scanner does it say "unable to connect" or something like that it?

It would be nice if everyone would come and say what fixed the problem but most don't. You can take their silence as confirmation that it was the PCM, if the problem continued they would most likely keep posting.

gordie_wi

Also very interested in hearing if a solution emerged... have the exact same symptoms (though the alternator seems tight and solid); highway driving; battery light came on, then engine light, then it died; does the exact same tach blip, relay clicking, then it levels off (in limp mode) and tach flat lines. Trying a used ECM (dealer programming today); they promised to check the alternator first. Would be interested in hearing if the relays were replaced (my "blue" one, next to the brown one, is the one that clicks).

gordie_wi

Just got word back on my 2002 Civic EX: the alternator checks out fine (installed tight, solid, grounded, putting out what it's suppose to) and with the used ECM installed and programmed; car is back on the road. While they said that it doesn't happen that often, the ECM itself can just bite the dust. I had the exact same symptoms and apparently the used ($100) ECM replaced and programmed fixed it (fingers crossed). Off to pick it up; will post if anything new transpires.

gearbox

iTrader: (95)

yay glad it got fixed

iteadjoseph

Same problem. My 2003 civic LX needs a new ECU/PCM. The dealer is asking $1000, and I'd much rather buy a used ECU and have them install it.

The problem is, the dealer says the part number is 37820-PLM-426...

...but all of the used ECUs I'm finding are 37820-PLM-L56 or L52 or L54.

Does it make a difference what the last 3 digits are? The mechanic at the dealer says everything needs to match exactly, but I'm not sure if he's just trying to get me to buy his part. Thanks for any help you can give!

ezone

Tech is correct. Many, many possible choices (8 or 9 I see for the entire fleet of 03 Civics) but ONLY ONE will be correct for your car.

Checked a US catalog

MSRP is $684 USD for just the part, plus a bunch of labor to replace it, and programming that you cannot do by yourself. You WILL be going to a dealer to have it programmed before it will run.

Majestic has it a bit cheaper http://www.hondaautomotiveparts.com/...VIN+Number+---

Your part number 37820-PLM-426 fits

Civic

2003 only

2 door DX
2 door LX
4 door DX
4 door LX

4 speed automatic (not manual or CVT transmissions)


37820 PLM L57 is the only other possible correct number I came up with, and it is obsolete through the dealer sources. That 426 number is what it superceded to.

HTH

iteadjoseph

Thanks for the assistance, ezone. That is substantially more helpful than a lot of the answers I've been getting from the dealer parts people. So do you think if I can find a used L57 on car-parts.com or elsewhere that it would work? Or does the fact that the 426 superseded it mean that I need to find that particular ecu?

ezone

No idea, but either one should work. NO idea what the differences would be either, that info isn't given.

Dealer parts people only sell parts. They normally don't have much knowledge of what it takes to make it all work. Techs don't normally want to give away secrets without getting a bunch of cash in their palm.


The L57 was probably an original part number installed when the car was new. You can't buy that number through the dealer channels now. Only the 426 number PCM is available as a new replacement unit, according to my info.

Did you look on your old unit to see its part number?

Have you fixed the problem that ruined your PCM? You probably don't want to ruin another one.



Regardless of whether you go with a used unit or a brand new unit, the immobilizer keys will have to be programmed to the new PCM before the engine will run.
Dealer only, unless you have a well tooled independent shop or well equipped locksmith in your town (phone first!).
We don't have that here in my town, I'm your final hope..


To save a tow bill (IF the engine still runs),
Gather up ALL YOUR KEYS for the car. They all have to be programmed at the same time.
Get the old PCM unbolted and ready to come out,
Then drive the car to the dealer. With all of the keys.
Check in at the service desk.
Pull the car around to the shop area (or wherever they tell you to park at so it is most convenient for the tech that has to do the programming) and
swap the new PCM in yourself, all it really needs is to sit in the hole and get all the wires connected correctly....
Let them do their magic, pay your bill, drive away.
Reinstall the glovebox and all that stuff at home in your driveway.

If the bad computer won't let the engine run, your dealer should be able to give you an "immobilizer brake code" and a method to input this so the car can start and be driven to the dealer on the new computer so they can get it programmed.
(I'm not 100% sure this will work with a PCM that has been used -- from another car. A brand new PCM should give about 4 "free" starts though, so you can drive it directly to the dealer as soon as it runs. Don't shut it off until you get there. After the last free start, it will not run again without the brake code or getting programmed.)





Did this for a customer (owns a used car lot) about 2 weeks ago on an Odyssey that had all sorts of trans codes. He parked at the bay door and proceeded to swap the computer himself (about 10 minutes to plug it in). I did the programming when he was ready.
I really hated to tell the guy that that computer was probably not the cause of the problems and it really needed a transmission job to fix his problem, but he wanted the computer done anyway. Oh well.
BTW, he forgot to bring the rest of his keys. LOL


HTH

Matt_75

If you're feeling lucky, you can trust the people on ebay.

01 02 03 HONDA CIVIC 1.7L AUTOMATIC ENGINE COMPUTER ECU ECM 37820-PLM-L54 OEM

MOST COMPUTER MODULES MUST BE REPROGRAMMED BY THE DEALERSHIP/PROFESSIONAL MECHANIC

TO INSURE DRIVEABILITY AND EMISSION STANDARDS.

PLEASE CONSULT YOUR LOCAL MECHANIC FOR DETAILS BEFORE PURCHASING THIS ITEM.

COMPATIBLE WITH THE FOLLOWING:

CIVIC 01 Elec Cont Unit (ECU); (ctr dash), (1.7L, SOHC), base, Calif, AT
CIVIC 02 Elec Cont Unit (ECU); (ctr dash), 1.7L (SOHC), base, US mkt, AT
CIVIC 03 Elec Cont Unit (ECU); gasoline (ctr dash), 1.7L (SOHC), base, US mkt, AT

Ident: 37820PLM426

Ident: 37820PLML51
Ident: 37820PLML52
Ident: 37820PLML54
Ident: 37820PLML55
Ident: 37820PLML56
Ident: 37820PLML57

ezone

AT/MT/CVT all require different PCMs. Multiply by:
DX and LX take one type
EX takes another (VTEC difference?)
GX is different again
HX is different too.
3 door takes yet another one.


Just for laughs, 37820-PLM-L54 subs to 37820-PLM-409. Neither came up under 01 02 or 03 Civic in my catalog search.

I'd say it isn't right. I'd only trust the numbers I posted, but I would really want the VIN from the car to be positive about this.

OP can look up his own parts!!
http://estore.honda.com/
Enter your VIN for the most accurate experience.


I'd trust ebay sellers about as much as I trust car salesmaggots.

iteadjoseph

Wow. Get this. So yesterday I call the guy at the dealer to get the exact part number from my car. He's says it's "PLM...looks like an A, then maybe an 8. I don't know, it's scratched off and kind of hard to see."

Today I just go there myself and ask one of the technicians to get the ECU from my car. They pull it, and you can read the sticker as clear as day. It's an L57! There's tons of those in the used market for about $100. I'm gonna get one tomorrow and have them install it, then reflash the keys.

I just can't believe the guy at the dealer straight up lied to me. Ridiculous.