Jump Star Delima

Went to jump start the XC90, connected the jumper; the positive to the positive connector next to the fuse box in the under the hood, and the negative to the strut stud. This is how I have always jump started cars, with this jumper. This time around, as soon as I connected the negative, I heard a "chukuum", and I immediately let go without any more connection. The only thought that came to mind was that my ECM got fried. When this happened, the jumper was at 98%; it went down to 0%. That is serious !!!

Isn't my connection the right way to jump start a car?
I have been jump starting cars with this unit a lot and in the same format.
What did I do wrong?
Attachment 9587

On these cars, jump starting this way sends transient voltage spike thru ECM and usually fries it.

You can get a replacement ECM via Xemodex.

In the owner's manual you will find procedure for jumpstart. Generally if you are using another car (call it 'donor car') it is to connect it more or less as you did but then just run the donor car for a while and charge the dead battery enough to start the car, takes 15-20 minutes, then disconnect the cars and start as normal to avoid any possibility of transients. Alternatively, use a 'jump box' which basically is a portable small AGM battery in a case with cables attached, pretty much as shown in the owners' manual.

Quote:

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Originally Posted by albertj

On these cars, jump starting this way sends transient voltage spike thru ECM and usually fries it.

You can get a replacement ECM via Xemodex.

In the owner's manual you will find procedure for jump start. Generally it is to connect another car (call it 'donor car') more or less as you did but then just run the donor car for a while and charge the dead battery enough to start the car, takes 15-20 minutes. Alternatively, use a 'jump box' which basically is a portable small AGM battery in a case with cables attached.

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In the past, I got a Throttle Body for one of the 2001 XC70 from XeMODeX, will contact them.

Just curious, are you saying I should not jump start a Volvo with the jumper I have? Jump started the XC70 a few times. Getting donor car would not always be a practical solution since, the dead car might be located in a place a donor car might not get to, which is why jumpers come very handy.

First, I should test to make sure the the fuses are not burnt then, check if the ECM got fried.

Thanks for the information.
Cheers

Of course you can use the jumper you have, however your process may need to change.

Use the process outlined in the owner's manual: https://volvo.custhelp.com/app/manua...nual/om_id/571 page 104. If you use a donor car, do not have the donor car running when you connect the batteries. Do not have the ignition key in the ignition in the car that needs a jump start (that way you are sure it's OFF), whether using a battery, a jump pack, or a donor car, when making the connections. If alternatively you connect a donor car more or less as you did but then just run the donor car for a while and charge the dead battery enough to start the car, it takes 15-20 minutes; the "telltale" is that the battery being discharged will make the donor car idle differently due to the load on the alternator. When you can hear that the load has decreased, then disconnect the cars and start as normal. Disconnecting avoids any possibility of transient voltage spikes or current fluctuations from the donor car.

Quote:

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Originally Posted by albertj

On these cars, jump starting this way sends transient voltage spike thru ECM and usually fries it.

You can get a replacement ECM via Xemodex.

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Please help me out here.
So the way I tried to jump start is wrong? Please what would have been the right way to connect?
I don't have a portable AGM battery, have always used portable jumpers on cars. Should I never use my jumper on Volvos and get the portable ADM battery, just for the Volvo?

Quote:

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Originally Posted by albertj

Of course you can use the jumper you have, however your process may need to change.

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The manual only shows how to jump start with a donor car, and the negative connection location. I would have thought the strut stud would give a better connection. So, would the "change" be not to use the strut's stud?

My ignorance would cost me $728 from XeMODeX.
Please, if there's a way, how can I test the ECM to make sure it's fried?

Thanks for your time helping me, well appreciated.

Just an update. Afterall, my ECM is fine. Connected the charged battery and all is well now.
Thanks all for your thoughts.

Cheers

Quote:

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Originally Posted by Oka

Just an update. Afterall, my ECM is fine. Connected the charged battery and all is well now.
Thanks all for your thoughts.

Cheers

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...sometimes the best way to solve a problem is a fresh look at it after a good night's sleep.

I am very glad you solved the issues.

Hello, I am still curious on why the issue ever happened.
Any thoughts or advice?