Hey guys, I just picked up a 2000 Prelude base 5 speed and I believe that the ECU is shot. I'm getting no injector pulse. I have spark, compression, and power to the injectors, but no ground pulse. I've checked all of the grounds, including the ECU ground on the thermostat housing and they are clean and tight. Still no pulse. Also something weird is that the OBD port goes dead while cranking.

So yeah, pretty sure that the ECM has gone bye bye. Now, I'm not keen on paying $500 for a new one, or switching to OBD1, so used is going to be my best option. Does it need to be programmed to the car, or is it plug and play? I don't want to **** off the immobilizer or anything else on the car.

 

You are not required to get another new one for your computer. You can use an old one as long as its the same part number as your previous ECU. Just make sure it is the correct one.

 

Cool. I always match up the numbers before I buy. Thanks.

 

You will need to have the ecu reprogrammed for the immobilizer to recognize your existing keys.

Are you using a noid light to check for pulse or an efi quick probe ?

It's not often an ecu goes bad. A lot of times when they do they have burned spots in them. I would check first. Also, check for 5 v reference at the map sensor and tps sensors with the ignition on.

 

Using a meter and a stethoscope. No clicking and no needle sweep when the ground engages. I can check for the power to the MAP tomorrow. I know there was one in the car, so they may have been having difficulties with it.

 

Popped a noid light on it today, just to be sure and it's definitely not getting a pulse. Just noticed that the ignition switch is acting up, sometimes not giving me dash warning lights in the run position. Swapping that out before I change the ECU.

 

Sounds good keep us updated.

 

Ignition switch fixed the dash lights, but still no injector pulse. Last thing to check is the wiring.