In the past we have burned up 3 coils in our distributors and the check engine light was always on. The computer we had at this time passed smog last year. We had a different computer that we changed out from the one that was in the car due to a repair. Our little 1990 Honda Civic 1.5 DX seemed to respond better on this computer and the check engine light went away. We made it close to a year without any problems. This year our little Honda wouldn't pass smog. We had a problem with a couple of sensors that had to be fixed. This computer had to be taken out and the original one we had put back in to pass smog because it was making the car run rich. We lasted 3 weeks and fried another distributor. Can the computer be causing this problem? The shop told us not to keep the original computer in the car and not use the replacement one. Thanks for your help.

 

can you tell me the letters and numbers on the side of each ecu , there is a little white sticker,
it looks like this

 

The computer can't burn out the coil. The usual reason for blown coils is excessive resistance in the circuit: the cap, rotor, wires, and plugs. If your plug wires are old or they are aftermarket you should replace them with a set of OEM wires.

You need to run the proper computer for your car. If you're doing that, and it still fails smog and there's no CEL, check the vacuum hoses on the fuel pressure regulator. If vacuum doesn't reach the unit, fuel pressure will increase and the engine will run rich. Another common reason to fail smog is the engine not warming up completely due to a faulty thermostat.

 

Sorry it took so long to reply to your request. We've had a lot of issues going on that needed to taken care of. We did get the numbers off the computers for you. The computer that was in the car when we purchased it ( we bought this car used and the motor had been replaced from another car) are as follows: 37820-PM5-L80 223-117327 MF. It also has 90.6.27 stamped on it in blue letters.

The replacement computer has the following numbers: 37820-PM5-A09 220-121620 MB
It has also has 89.10.16 stamped on it in blue letters.

Does the 90 and the 89 in the blue letters mean the year of car it came out of?

Thanks for your help again.

 

weres the ecu?

 

yes the blue stamp is the date of the ecu's

stevencivic the ecu is under the carpet on the passenger side,

is your car auto or manual cause the pm5-a09 is a manual ecu, and the pm5-l80 is a auto ecu, this may be the reason of a cel light, now in the center of the ecu is a red blinking light when you turn your key on, can you turn your key on and count the blinks for me, each 1 sec blink = 10 and each 1/2 sec blink =1 there may also be more than one code, count a few times to make sure you got it right, the blinks will repeat the codes.

 

All the flashes seem to be 1/2 second apart. It looks like there are 2 codes. The first one has 12 flashes and the 2nd one has 19 flashes. We watched it 6 times and it stayed consistent. Our car is an automatic and it ran stronger on the standard transmission computer and the cel didn't come on. As soon as the original computer was put back in the cel came back and it hasn't left since. This probably sounds funny but with standard transmission computer our little Honda shifted fine and had more power. Does this make sense?