Bad Emc?

**Maggiejack** · #1 05-19-2017, 09:35 AM

I'm looking for for some input before sinking more money in my lr3. Here's the situation. Drove the truck all weekend with no problems whatsoever. Monday morning try to start. After about a one second delay after turning key, the truck starts. Immediately get engine fault, hdc fault, transmission fault, very rough idle, and maybe another couple messages. Truck starts every time but stays in limp mode. Towed to local lr mechanic who claimed to be a very unusual problem based on the dozens of codes it was throwing. Their recommendation is to replace the emc ($2800) as the first step to fixing the problem. They couldn't guarantee that as the problem but thought it was most likely. Also they say the alternator is testing marginal as it is charging with 13.39v. I'll attach the full report from the mechanic.
Does anyone have any suggestions before going with their recommendations. I'm hesitant to go their way because everyone I've talked to say an emc failure is very rare.
Thanks in advance

**Maggiejack** · #2 05-19-2017, 09:37 AM

Also forgot to mention. 2006 lr3 hse w/ 110k miles

**Drillbit** · #3 05-19-2017, 09:38 AM

Swap the alt first. Low power can make trucks do weird things. Mileage? What engine?

**Maggiejack** · #4 05-19-2017, 10:43 AM

4.4l with 110k miles. Thanks for the response

**discostew** · #5 05-19-2017, 12:05 PM

You need to show that truck to someone else.

**squirt** · #6 05-19-2017, 12:07 PM

I'd suspect the battery and it's connections before anything else, if you're seeing a cornucopia of fault codes. A bad alternator may have ruined it, but a good, fully charged battery with fresh, clean connections is a good diagnostic tool. The delayed starting is also pointing me in the same direction. Their suggestion that the PCM and TCM failed at the same time seems a bit ludicrous to me.

**Maggiejack** · #7 05-19-2017, 12:51 PM

Thanks for the responses. This morning after posting I did a hard reset on it. The first time after the reset it started up right away(no delay on starting). The amber check engine light was out but the red battery light was on. The display said engine fault. It was still in limp mode and idling rough. Putting it in gear made it run smooth but limited to about 1400 rpm. After shutting it down and starting second time the amber check engine light came back on. I'll give the new battery and alternator a shot.

**discostew** · #8 05-21-2017, 08:07 AM

So just to be clear. You would rather go out and spend a thousand bucks or more on that stuff without showing the truck to somebody who knows how to fix it for about 130 bucks.

Maybe you should consider having the truck diagnosed before you go spending any money on parts.

**Maggiejack** · #9 05-21-2017, 08:29 AM

The truck has been taken to a reputable Land Rover mechanic. On my original post I included a picture of their write up of what they think the problem is. They stated to me that this is an unusual problem based on the codes that came up. They couldn't guarantee that the $2800 that they quoted me would fix the problems. I am asking on here if anyone had any other ideas before I drop all that money for something that might not even work. I've been told by numerous people that Emc failures are very rare.

**discostew** · #10 05-21-2017, 09:17 AM

Quote:

Originally Posted by Maggiejack

The truck has been taken to a reputable Land Rover mechanic. On my original post I included a picture of their write up of what they think the problem is. They stated to me that this is an unusual problem based on the codes that came up. They couldn't guarantee that the $2800 that they quoted me would fix the problems. I am asking on here if anyone had any other ideas before I drop all that money for something that might not even work. I've been told by numerous people that Emc failures are very rare.

And I looked at that invoice and recommended you show it to someone else. The fan they want to replace your ECM for isn't even part of the ECM. So after you spend that money your still going to have to fix that fan, He will probably tell you that the " Fan took out the ECM, You needed both"

These guys are right that the alternter will cause a lot of stuff. But a broken wire will make the alternator not charge. There is also a communication buss between the alternator and the ecm. I always check the data stream to make sure the commanded charging dwell is settling in around 60%. I've seen ECMs cause that # to be way off as well. It's a complicated charging system, alternators are failing so it really could just be that.

And those other faults with your throttle checksome error is more likely to be a throttle peddle or throttle assembly also.

**Maggiejack** · #11 05-21-2017, 10:09 AM

Thanks for the advice. It is currently at another shop. Hopefully they can find that $130 fix.

**Maggiejack** · #12 05-23-2017, 09:17 AM

Here's the latest. I took the truck to another shop for a second opinion. They agree with the first place. Their recommendation is to replace both the alternator and ecm to the tune of $3500. Does anyone know if it's possible to buy a used or refurbished ecm and have it work in my truck? If so, would I have to take it to a lr dealership to have it programmed?
Thanks

**jymmiejamz** · #13 05-23-2017, 10:04 PM

My question is will these shops stand by their diagnosis if it doesn't fix it?

**discostew** · #14 05-24-2017, 06:24 AM

Quote:

Originally Posted by Maggiejack

Here's the latest. I took the truck to another shop for a second opinion. They agree with the first place. Their recommendation is to replace both the alternator and ecm to the tune of $3500. Does anyone know if it's possible to buy a used or refurbished ecm and have it work in my truck? If so, would I have to take it to a lr dealership to have it programmed?
Thanks

I've been working on these cars for a long time and replaced maybe 2 of these ecms. I'm thinking the odds are against you really needing an ECM. But to answer your question no. I don't believe you can program a used ECM to your vehicle. It has to do with the VIN # being burned into them to avoid people stealing your truck to get those expensive modules.

**lordhelemt** · #15 05-29-2017, 06:57 PM

Check the wires under the front passenger side sill for corrosion. You may want to pull the seat to have better access. Dig deep into the roll of wires and repair any all faulty connections. Also check up to the kick panel. There will be a couple of 16 pin connectors. Look for corrosion there too. My $ is one of the wires is rotted out at the pin

**jmonsrvr** · #16 05-30-2017, 03:34 PM

so I'm guessing they checked your alternator, battery, wiring?

sounds like an awfully expensive fix for a 'maybe'. Codes can be thrown in error. Especially when you have so many stacked up at once.

Good luck!! (report back)

**Maggiejack** · #17 05-30-2017, 04:50 PM

It's still in the shop. I took them a screenshot of discostew's and lord helmet' posts to check out before we start replacing parts? Anyone interested in a project lr3 in the Denver area?