Hello,

I have a 92 civic dx manual with 188k miles
My son drove it to School had it towed home.
The engine cranks over but it won’t start.
I’m not getting fuel over to the fuel rail.
I have no pressure.
I got no problem codes.
Check engine light never came on.

I Checked and replaced fuel pump relay no fix.
I Checked and replaced fuel pump no fix.
I checked and replaced ICM along with Coil no fix.
I replaced all these parts because the car is over 13 years ald and I've never really had any problems with it.
I plan on keeping this car for another 10 years or so Hondas are great cars.

What I’m I missing here guys?

Thanks,

I suspect the voltage going from your ECM to the MAP sensor is the problem. Check for 5v. Going to the MAP sensor's reference wire (+) and ground. It's probably a fraction of a volt, indicating the ECM is failing. If the signal wire from the MAP sensor is real low, you won't get spark and the fuel system will shut down. This is the KEY sensor on Hondas and a major design flaw, in my opinion. They should have designed a more fault tolerant electrical system. The real test is to turn the ignition switch OFF, disconnect the D harness to the computer, turn the ignition switch ON, and measure the voltage between computer pins D19(+) and D21(-). If there is less than approximately 5 v. then substitute a known good ECM. If you have approximately 5 v. between D19 and D21, then repair an open between the ECM and YEL/GRN reference wire going to the MAP sensor. Odds are your computer has failed and it's time to replace it. MAP sensor failure is another possibility, as well. Both are easy to check out.

In return for the help, let me know the ultimate solution.

I get only about 300mvdc at the MAP sensor connection.
I'm having a problem IDing pin D19 and D21 at the ECM My book is real generic and basic.
I'm not sure if I mention that I get no codes but the check engine light stays on all the time and never goes off.

Thanks,

The odds are your MAP sensor test confirmed your ECM is bad. By the way, the check engine light staying on and no codes being thrown are characteristics of this problem. Checking the voltage at the ECM only confirms that you do not have an open between the ECM and the MAP sensor. Honda wants about $850 for a new ECM. I suggest going to O'Reilly Auto Parts and buying an A1 Cardone remanufactured ECM, with a lifetime warranty, for around $260. I'm certain this will solve your problem.

ECMs are nothing more than "power transistors," whose job is to supply the proper voltage to a host of sensors, under constantly varying conditions. Some websites bogusly claim the odds of a Honda ECM going bad are virtually zero. Don't believe it for a minute. When you remove your ECM, disconnecting the negative battery terminal first, look at the heat discoloration on the metal covers. You will observe a spiral blue pattern. ECMs don't have fan motors to cool them and, to make matters worse, are covered by carpeting. Heat, vibration, and shorts reduce their lives. You did well getting 188,000 miles out of your ECM. Once you replace it, your car will fire right up, run like a top, and the check engine light will go out. Most Honda technicians are in the dark when it comes to diagnosing the situation you encountered. They don't understand the vital significance of MAP sensors in Hondas. They are the single most important transducer in these cars. If they don't get the proper voltage, your ignition and fuel systems shut down. You will have just saved yourself a lot of money and learned some valuable information about trouble-shooting your car. It's all in the diagnosis, not in "replacing and playing." Too many main relays, fuel pumps, ICMs, and coils are being unnecessarily replaced for a "won't start situation." Even the Honda Shop Manual did not include this test for this situation. Spread the word and help others.

Please keep me posted with what happens.

So what did you end up doing?

Quote:

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Originally Posted by txgreasemonkey

So what did you end up doing?

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Well I ended up purchasing a used ECM from my local junkyard $125 from a 95 civic.
I would like to thank you for all you great input, I would not had been able to figuire it out with out your help.
THanks, :D

Your posting makes my day. Thanks. I was really interested in your situation and I'm glad you were able to fix it so reasonably. You're a good dad and I'm sure your son appreciates your effort.

Good day txgreasemonkey,

I have the same problem as civicdx92.

I only get more or less 2V on D19 and D21 of the ECM(tested that while the ECM was unbolted from the body of the car, I don't know if there will be a grounding issue). I checked the map sensor pin connector and it gave me the same reading (ECM was unbloted from the body).

I suspect my ECM is bad also, but sometimes it does work!
After several times of turning the ignition key back and forth sometimes the CEL goes out and the engine will start OK.

So I isolated any problem with distributor.

I had my mitsuba relay resoldered, and I can hear it click.

Is my ECM bad? I would want to change it but the OEM is quite expensive and I doubt the reliability of a used ECM because it might perform just like mine?

Please help

Thank you in advance.

kean, I'm sure your ECM is bad. Try and buy a remanufactured ECM with a lifetime warranty. You can buy a Cardone ECM from O'Reilly Auto Parts, with a lifetime warranty, for $293.99 in the U.S. Other outfits sell Cardone ECMs but only with a 1 year warranty. Here's O'Reilly's offering:

CARDONE INDUSTRIES - Remanufactured Electronic Control Unit
Part No: 72-2048
1 Per Vehicle
Limited lifetime warranty
w/OEM #37820
P06
A00, A01
ENG CTRL MODULE
w/MAN TRANS
EXC CALIF
Our Price: $293.99


Each
[Core: $70 ]

Quote:

---

Originally Posted by txgreasemonkey

kean, I'm sure your ECM is bad. Try and buy a remanufactured ECM with a lifetime warranty. You can buy a Cardone ECM from O'Reilly Auto Parts, with a lifetime warranty, for $293.99 in the U.S. Other outfits sell Cardone ECMs but only with a 1 year warranty. Here's O'Reilly's offering:

CARDONE INDUSTRIES - Remanufactured Electronic Control Unit
Part No: 72-2048
1 Per Vehicle
Limited lifetime warranty
w/OEM #37820
P06
A00, A01
ENG CTRL MODULE
w/MAN TRANS
EXC CALIF
Our Price: $293.99


Each
[Core: $70 ]

---

hello txgreasemonkey,

sorr for not being convinced but I looked for a same model car and we switched our P27 ECM, his ECM just worked fine with me, my ECM was really bad. For the moment I will just buy a used ECM to be able use the car. But I don't think it will stay long since it will be the same age as my ECM and the probability of failing is high. That includes humid, hot, and cold weather, and more places are flooeded during rainy days.

I plan to keep the car for long since it is my 1st car.

looking for branches of Cordone Industries, I found one in mississauga ontario canada where most of my ralatives live. I hope they have a stock

I will just ask them to buy me one and give it to me on their next visit to us this November.

thank you very much for your help

Txgreasemonkey,
I also have similar prob. I show no voltage between 19 & 21 at the ecu but I show .12 at map sensor. Is that possible or am I doing something wrong? I have 2 ecu's, one is supposed to be known good. They both measure the same voltages. I'm pretty sure I have fuel pressure as I hear it buzz for a couple of seconds at key on. Just no spark...
Thanks,
Mike

Your description is an impossibility. You must have at least .12 v. at the ECM, if you record .12 v. at the MAP sensor. Are you turning the ignition ON, when you record your readings at the ECM? No matter, your readings are SO low that both ECMs are bad, if you are running the tests properly. Is your DMM set for DCV?

I think I just figured out what you are doing. You are testing for voltage on the D19 and D21 "female" connector. That's why you are reading zero volts. You need to test the voltage on the ECM's "male" pins.

Do you hear your fuel pump run, when your ignition is turned to ON? Does your Check Engine Light stay on?

Where did you go?

You are correct... I was checking female end (DCV). The fuel pump runs for a couple of seconds after turning the key on and the CEL comes on and then goes off about the same time as the fuel pump stops buzzing. I have to go to work... I will test again this afternoon. Thanks for your help.

You already have a known good ecu then why don't you just plug it to ecu harness and check if there will be approximately 5V on MAP sensor pin?

Or just start the engine.

Having a solid CEL is one sign of a bad ecu, and you can't retrieve any code.

In your case having a click in the main ralay and fuel pump goes off after 2 secs as well as the CEL, isolate the problem with a bad ecu.

Once you fixed the problem, you may try to use your old ecu and check if it works.

At this point, I don't think your problem is going to be your ECM. Just for the heck of it, though, take a MAP sensor connector reading on the right most wire and let me know what you get. Make sure you get a really good ground on the black test lead. Press the lead into the G101 bolt, where the ECM grounds.

I'd focus more on your distributor; e.g. igniter and coil.

Ok, I have 5 vdc leaving the ecu to map and I have the same voltage at map sensor. I didn't have a good ground in previous test.
Here's where I am... I have battery voltage at both coil leads/ICM (key on). I have 9.7 at the other lead on top right of ICM... Battery voltage (12.5) at the lead on the side of ICM. I have to wait until some gets home to measure voltages while cranking. I read somewhere I should test at coil +... connected and disconnected whil cranking. Is that correct?
If I didn't tell you before, I have a solid CEL when 2 pin connector is shorted @ ECU. No error codes. If I remove the jumper from 2 pin connector, CEL goes off like normal after a couple of seconds after key on... fuel pump buzzes during the couple of seconds.
Thanks much for the help.
Mike

Based on the age of your Civic, I'd replace the igniter, coil, rotor, and distributor cap. I'd recommend this, even if your car started. You are at the stage where you don't want things to go bad on you one at a time. Go for "like new" performance and put some new parts in it. Advance Auto has the cheapest ICM and RockAuto.com has the best price on coils. O'Reilly Auto Parts sells Wagner rotors and distributor caps with brass contacts and a lifetime warranty. Hondas are notorious for problems with ICMs, coils, and main relays. Just my opinion, though.

Let's go back to the MAP sensor connector for a minute. With the ignition ON, what voltage do you get between the YEL/GRN reference wire+(right wire) and the GRN/BLU neutral wire-(center wire)? How about between the WHT+ signal wire (left wire) and the GRN/BLU neutral wire-(center wire)?

My wire colors are different than you describe... yel/red -- grn/wht -- what
Between yel/red and center 5.0 vdc
Between white and center 3.5 vdc
Mike

The voltage between WHT+ (D17) and center- (D21) should be 5 volts. Here's what you need to do. Disconnect negative. Battery terminal and remove the "D Harness" from the ECM. Then, reconnect the negative. Battery terminal and turn the ignition ON. Measure the voltage between male pins D17+ and D21- on the ECM. Tell me what voltage you observe.

3.54 vdc @ ECU, between d17+ and d21- (When I measure it starts at 3.9 and quickly drops to 3,54)

Just to add... same voltage on both of the ecu's

I believe both ECMs are bad. You should've read 5 volts! To me, this is why your Civic won't spark and ties in with the Check Engine Light staying on, when the service check connector terminals were jumped.

Remember, the MAP sensor controls timing (similar to the old vacuum advance on distributors) and air/fuel mixture, depending upon manifold pressure changes. Like any transducer, it converts energy from one form to another. Here, it converts throttle body vacuum pressure changes into fluctuating electrical current signals to the ECM. If this sensor does not receive the proper voltage from the ECM (basically, a giant power transistor), you will experience catastrophic ignition and fuel system failure.

Is it odd that both ecm's measure the same voltages? Have you ever tried to repair the ecu? Do you know which chips go bad?

That's way over my head. I've been told that, over time, the electrolytic capacitors start to leak on the 1989-94 ECMs. Heat is the big culprit. Do you see blue swirls on the covers? If you open them up, you may see several microprocessors that are "crazed" from heat. Vibration and heat can also affect these "giant circuit boards," just like Honda's main relays, causing cold solder joints. Buy a remanufactured Cardone ECM from O'Reilly Auto Parts for around $255 with a lifetime warranty. Other outfits only give you a 1 year warranty. Another alternative is to buy a used one on EBay for around $110, freight included. Some might come with a 1 year warranty. New ECMs from Honda are over $850, plus tax, and only have a 1 year warranty.

Where did you get the second ECM? Yes, it's very interesting. Both could have been damaged in the same way; e.g. not disconnecting the negative. Battery terminal when working with them. It's hard to tell.

Honda Civics will go 350,000 miles, if you take care of them. I keep my cars for a long, long time. If you like the car and would like to keep it for a long time, then I'd put a new ECM in it.

You can perform other tests, but I don't think anything else will get it to spark. Tell me about how your problem began. Was it sudden?

Yea it was sudden... going down the road about 45 and just died. I checked for spark and fuel first thing. I had no spark and I smelled fuel at the exhaust after cranking the engine over and heard the fuel pump as usual, so I figured I had fuel pressure. I opened the distributor and saw a small amount of oil inside. I figured it was enough to short out the igniter or ICM or whatever the heck it is. I bought a remanufactured distributor and it still had no spark. I returned the distributor and searched the net and found someone saying if I had a solid CEL on shorted service connector I had bad ecu. I also bench tested the main relay... it's fine. So I bought an ecu off Ebay for $90. I have an email to the seller to see if it can be returned. I probably get to eat it.

Sudden death situations are often caused by computer failure. People think these ECMs (particularly Honda) are bullet proof, but they are not. Makes me think even more that its your computer.

Here are the likely culprits, when you don't get spark: ECM, igniter, coil, rotor, distributor cap, wires, main relay, and MAP sensor. ECMs and igniters are the usual culprits--both solid state. They either work or they don't.

I really appreciate all your help. I'm also a believer in Honda. This is the first time one has laid down on me. I'm thinking about an buying an Insight. Maybe now is a good time.
Just thinking out loud here... do you think any other sensors / transducers being bad could cause this condition? (I understand there are other sensors that effect the spark... )

If your car is in otherwise good shape, I wouldn't get rid of it. The MAP sensor is the "Key" sensor on Hondas and is the only one capable of knocking out spark and fuel. The same can be said for the ECM.

Somebody else will come along and get your car for a steal, put in a remanufactured ECM, and drive it for years. Trust me, I've seen other people get frustrated with otherwise fine cars and sell them to an individual who knows what he is doing for peanuts on the dollar. Good way to make a living, if you wanted to. You are on the verge of a great personal victory--don't stop now.

How many miles are on your Civic?

Ok,OK... I'll have to save for a couple of weeks for the parts. I'll post back after the next round. Thanks again
150,000 mi give or take... run hard and put up wet...

Hang tough and never, never, give up!

zortmo, here is what it would cost to replace the crucial ignition parts and get a new lease on life:

Ignition Coil (RockAuto.com), Part No. 30510PT2006, $36.79
Main Relay (RockAuto.com), Part No. RY422, $38.89
Igniter, Advance Auto, Part No. 115070, $69.88
ECM, O'Reilly, Part No. 722048, $256.99*
Total $402.55

* Have O'Reilly match Advance Auto's price and get a lifetime warranty for the same price.

You may try to test both ecu to a same model car/engine and see if it works so you could isolate the problem with it.

I thought several times trading my honda to a corolla bacause toyota is known to be very reliable, but when I had the chance drive the corolla, I realized that I get more pleasure driving my civic, damn fast for a SOHC but economical.

I hope you've seen some souped and very well dressed civic around your place, I'm sure you'll think twice before getting rid of it. The EF,EG, and EK civics are good looking and I think even after 10years it will still be.

The good thing about having a problem like this is you learn about your car.
And if you encounter the same problem in the future, you already know how to solve it. Save money on labor cost.

Just change the crucial parts as txgreasemonkey had stated and you will feel your car perform like it was new. Anyway those parts are part of the car's service maintenance, don't be sad to spend few bucks, you will benefit from it in the long run.

zortmo, try this test:

. Turn ignition switch OFF
. Reconnect the 3P connector to the MAP sensor
. Turn ignition switch ON
. Measure voltage between D17+ male terminal and D21- male terminal on the ECM
. Record the voltage and let me know the reading.

Fixed it... finally. The first distributor I bought was bad. I got another one and it fired right up. I was able to rule out the ecu by using a logic probe to verify the signal between ecu and ignitor. It had to be in the distributor... I bought one from Oreilly with all new oem parts and a lifetime warranty for 175.00.
Thanks for the help and the inspiration to stay after it. Great forum.
Mike

Good job. That's got to make you feel really great!

I was having the same problem with my 92 civic not sparking. I finally figured out from this forum how to test the ECM by map sensor voltage and it tested bad. So I got a used one and it started up just fine and worked for a day. I ran a engine code test and got straight blinking... nothing I could discern different from long - short blinks. They all seemed the same to me and just kept blinking(Is there something wrong with that?). Now today I go to start it up after work and it won't start again. So I checked the engine code again and got a bad ECM signal.

So my question is, what is it that is killing the ECM? Is there a short somewhere that is frying it? If so, how do I diagnose it?

I've noticed for a while that every time I try to get out of my car I get shocked when I touch my door, which was annoying at least, but got me wondering if there was something wrong. Next thought is that the door locks randomly quit working and I don't remember being shocked before that. Could that be the culprit?

Doug777, it's very important to disconnect the negative battery cable, before working on the ECM. You also should ground yourself first, so you don't short out the new ECM.

This link may help:

https://www.askmehelpdesk.com/cars-t...tml#post235038

Quote:

---

Originally Posted by txgreasemonkey

Doug777, it's very important to disconnect the negative battery cable, before working on the ECM. You also should ground yourself first, so you don't short out the new ECM.

This link may help:

https://www.askmehelpdesk.com/cars-t...tml#post235038

---

Yup... I read through all that before and did it all step by step. The negative cable was disconnected when I did the swap and I reconnected it afterward. I was also grounded to the car body when I did all the work. It ran and I drove it about 2 miles, put it to sleep for the night, and drove it another two miles to work in the morning. When I went to start it again when I was done working it wouldn't start and that's when I did the engine code check and got the bad signal.

Now I'm just trying to figure out what is causing the ECM to go bad? There has to be something screwing it up for it to be going bad after 15 minutes of driving.

Doug777, was the replacement ECM an exact part no. match? When I replaced my ECM two years ago, I bought an ECM with a lifetime warranty from O'Reilly Auto Parts.

Try applying dielectric grease to the ECM's connectors.