Can I start an engine with a dead ECU?

[svdsinner]

I think that the ECU I replaced last summer died again. (Cranks but doesn't fire, and the ODBDII interface won't connect) If it is reasonable, I'd like to get it to run long enough to drive the 4 miles to the shop that will look at it rather than hassling with getting it towed.) I know that at minimum, I'd have to jump the fuel system and ASD relays. Anything else, or is the engine not going to start with out a functioning ECU?

Also, the issue seems to have happened at the same time my battery froze. (It was under a year old and defective. I replaced it under warranty only to discover the dead ECU.) Dumb coincidence or could one have caused the other? Anything else I may want to check on to make sure there isn't some other root cause both killing batteries and/or ECUs?

 

[BWL]

I'd check your voltage regulator. Overcharging and too high a voltage would damage both things. Keep a close eye on voltage when you do get it running again. The ecu also adjusts timing as well so I think towing it is your only option or at the very least best. You could spend a lot of time trying to get it started without the ecu with a slim chance of success. Also risk damaging other electrical components.

 

[crazzywolfie]

have you checked your fuses? the battery probably shouldn't have froze. you might want to try heating up the ecu with a heater or hair dryer if you think it might be the issue. i have heard of some trucks not starting when the ecu was cold but started when stored inside. it is usually a bad ecu but it might get it running enough to get to a shop

 

[BWL]

If it happens to be a 3rd gen diesel the first thing I'd check is the battery terminals. They tighten on both sides on some of them and I kept boiling the right side battery until I tightened the left side terminal. Also wouldn't start and did after I tightened what felt like an already tight terminal. 2 dealers and an alternator shop couldn't figure it out. My home dealer figured it out in about 5 minutes because they have a good troubleshooter. I think the sensor gets power off the drivers side of the positive terminal on the drivers side battery.

 

[dudeman2009]

It has been suggested quite a bit, but charge that battery. If it went dead it's likely the PCM lost its settings. Try giving it some gas while starting on a freshly charged battery, it may not know where to put the IAC in order to get it to idle. Just make absolutely sure the battery isn't frozen when charging or it may explode, 24hrs inside is enough to ensure it thaws completely. Also, check the ground straps from the battery, PCM and firewall to ensure they are all secure.

 

[svdsinner]

have you checked your fuses? the battery probably shouldn't have froze. you might want to try heating up the ecu with a heater or hair dryer if you think it might be the issue. i have heard of some trucks not starting when the ecu was cold but started when stored inside. it is usually a bad ecu but it might get it running enough to get to a shop

It supposed to get up to 40F this week. (The freezing happened at -10F) Should that be enough to try again?

Also, as far as the battery, I charged it the easy way and had it replaced for free under warranty. The sides were bulges and there was obvious damage to the plates. The store's tester system confirmed it was dead and not coming back.

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