maestrotwo

I am new to the site and have been trying to find out how to troubleshoot a 1996 Honda Civic 1.6 that keeps blowing the number 44 fuse. I found a thread that said to check four components in order and then repost. I have done that. The four components were:

1. main relay,
2. 4 fuel injectors,
3. IACV,
4. ECU connector A.

The person posting had a problem in another place than I do. I checked the first three components and when I disabled them my fuse kept blowing. When I unplugged the ECU, connector A, then the fuse doesn't blow. Where do I go from here? Thanks in advance for all the help. Love this site!

Addition: I forgot to mention that the fuse only blows when you actually try to start the car. Just turning the key to the "on" position does not blow the fuse.

Murray

Former User

Replace the ECU.

maestrotwo

I will, thank you. Do all of the numbers have to match exactly on this? I have read the posts of the significance of the numbers but have seen where some people say that some of the numbers may not have to match exactly.

These are the numbers 37820-P2E-L01-901-114655

The car has a 5 speed manual transmission and the engine number is D16Y7.

Thanks again for the help.

maestrotwo

I replaced the ECU. All numbers match except for the last series of numbers. The battery was unplugged until all connections were made and the unit secured. I hooked up the battery and attempted to start the car. It tried and actually ran for about 5 seconds. Then...the fuse blew. I replaced it and two more times and it blew instantly. Any suggestions?

Thanks.

Former User

Redo^ this test. Same result?

maestrotwo

I will run the test tomorrow.
Thanks.

maestrotwo

I did the test again. With the battery disconnected, I installed the new ECM. After hooking up the battery, and with the A connector unplugged from the new ECM, the fuse does NOT blow. (the same result I got on the old ECM) By the way, on the new ECM, the first 4 sets of numbers match my original EGM. The last set of numbers does not match. I was told that this would not be an issue. I hope that is correct.

Is there something that I have missed? Thanks again for your time and help.

Former User

Post the two entire ECU codes, though it won't likely be the problem.

The test points to a bad ECU. Do you have a friend with a 96-98 Civic that you could install the ECUs to see if they cause fuse 44 to blow?

Also, for your car, does fuse 44 only blow when the key is turned to ON(II) or when key is OFF?

maestrotwo

I may have a way to use a friends. I will have to check on the year of his car though. The fuse only blows when I actually spin the engine. If I turn the key to the "on" position the fuse remains in tact. The first time I tried to start the engine it actually "ran" for about 3-5 seconds before the fuse blew. After that, the fuse would blow as soon as I tried to start the motor.

Former User

I missed this^ important information. Let me look at the circuit again.

Former User

When you do this^ after installing a new fuse 44, does the fuel pump prime for 2 seconds?

Is the fuse labeled 44 in the diagram below the one that blows?

maestrotwo

i plugged in the A connector and turned the key to the "on" position but I hear nothing. When the fuel pump primes it should be making a sound, right? Also, according to the diagram that is the correct fuse.

Former User

The fuel pump should run for 2 seconds when key is turned to ON(II). Remove gas cap and put ear to hole to hear the fuel pump buzzing when it runs.

When you do this^ with new fuse 44 installed, does the CEL turn on for 2 seconds and then turn off?

Do you have a spare working main relay? Can you borrow one?

maestrotwo

I don't hear anything when I turn the key. No fuel pump sound. What is the CEL? And should I have the A connector plugged back in for the fuel pump to work?

Former User

Plug in connector A and main relay. Turn key to ON(II). You said fuse 44 doesn't blow, but does the pump prime?

CEL = Check Engine Light (engine illustration) in cluster

maestrotwo

Okay. Plugged in Connector A. Turn key to on position. I hear no fuel pump prime. No CEL light on the dash. With Connector A plugged in the fuse blows.

Former User

You previously said that fuse 44 does not blow with key in ON(II) but that the fuse does blow with key in ON(III). What changed?

maestrotwo

When I listened for the fuel pump I didn't have connector A plugged in. Didn't know if that connector had to be plugged in to run the fuel pump so I plugged it in and my fuse blew. Sorry. Anytime I have Connector A plugged in the fuse blows in on(II) . If it is NOT plugged in the fuse does NOT blow in on(II).

Former User

Do the following test.

1) Unplug only ECU connector A.

2) Turn key to ON(II).

3) Ground pin A16 (Grn/Yel wire) in unplugged ECU connector A to the metal frame under the dash.

Does the fuel pump run as long as A16 is grounded? Or does fuse 44 blow and the pump doesn't run?

maestrotwo

The fuel pump runs and the fuse does NOT blow.

Former User

This^ test result again points to a bad ECU.

maestrotwo

Since this one is used I guess it could be bad as well. They said it had no codes and was working when taken out of the vehicle. . What is your advice...should I pay the money and order a new one or try another used one?

Former User

Can you borrow a known good ECU?

maestrotwo

I am not sure. I will check on that tomorrow. Again, thanks for the help.

Former User

You could also de-pin the A11 and/or A24 Yel/Blk wires in ECU connector A using a tiny flathead screwdriver to see if fuse 44 is prevented from blowing when ECU connector A is plugged in.