2001 V70 2.4T did not start immediately after replacing the battery

BladeRider · Post by **BladeRider** » 07 Apr 2018, 06:55

Hello all! I'm new to the site and new to Volvo cars. Relatively recently (November 2017) I purchased an old 2001 Volvo V70 2.4T with 300000kms (built in the late 2000 but VIN says 2001 model). It's working alright for it's age and mileage, but this morning, for the first time and out of the blue, it refused to crank the engine. I measured the battery voltage and it was below 12. Went to the store and purchased a brand new battery (12.64V disconnected). I installed it and attempted to start the engine. No cranking... I tried several times with the same result. Then I connected the voltmeter to see if the voltage drops too much when I try to started. Well, I couldn't measure it, because as soon as I turned the key it sprung to life and settled into a nice idling. I went in town to run some errands and is started all the time and the cranking is vigorous. I can't explain this behavior. It took about 5 minutes from the time I installed the new battery until it started.

So my two questions are:
-Is there something that would prevent it from cranking for a few minutes after sitting without battery? The immobilizer maybe? Or I should worry that the starter motor is about to go?
-Is a 0.2V drop after connecting the battery normal, or the car draws too much current (12.64V disconnected and 12.42V after connecting the battery to the car. (not sure the measurement is valid though as the car runs some accessories already when you unlock it)

The old battery didn't give any warning and the car always started until this morning. Charging voltage is around 14.2V. The old battery was calcium-calcium (95Ah) and I read that older cars don't charge them properly because they need a bit higher charging voltage so I preferred to replace it instead of attempting to recharge it as I need the car this weekend and I had no idea how old the battery was.

Thank you for your time!

Post by **abscate** » 07 Apr 2018, 07:52

You probably had an immobilizer reset when you changed batteries.

0.2V is too large a drop, but there are things that run on these cars with key off. Let it sit with the hood up for an hour and measure voltage then. Oh wait, the trunk or boot should be up

BladeRider · Post by **BladeRider** » 07 Apr 2018, 09:00

Thanks! Perhaps I could leave the voltmeter in the trunk already connected and read the voltage after one hour.
I didn't know about the immobilizer reset. Thanks!

Post by **abscate** » 07 Apr 2018, 13:38

Hmmm, rethinking

If they immob trips on a P2 I think it cranks but does not fire...

BladeRider · Post by **BladeRider** » 07 Apr 2018, 19:24

Well, then I'll wait and see. So far today it started all the time after the initial problem went away. And I started it at least 10 times throughout the day, because I used the car a lot.

Post by **abscate** » 08 Apr 2018, 05:38

It might be that P2 cars stop cranking on an immobilizer fault, someone here will know that.

I wouldn’t worry about it if it is working now, though.

BladeRider · Post by **BladeRider** » 08 Apr 2018, 06:13

Thank you. Yes, I think that a bad starter motor would give intermittent signals before giving up its ghost

permanently. Any idea how reliable the starter motors are on these cars?

Post by **abscate** » 08 Apr 2018, 07:01

Very reliable. If you search for ‘starter bypass , in this forum you can find the wire that lets you bypass the immobilized system for cranking , I think your 2001 has the same wire?

Ah, no. You don’t get it on a P2 car as it’s controlled by the CEM

If you know electricity you could pull the starter relay and apply 12v to the terminal 5 at relay 2/37 2/35 per the above, with car in park and hand brake set.

BladeRider · Post by **BladeRider** » 08 Apr 2018, 13:27

Thanks for the diagram. Is that relay 2/35? I see no 2/37 and 2/35 - 5 goes to the motor.
I also have the Haynes manual, I'll take a look there if need arises again.
Good to know the starter motors are reliable. I have other things planned, like rear suspension, and a diagnostic tool for SRS before worrying about the starter. At least that's the plan.
Thanks for all your help.

Post by **abscate** » 08 Apr 2018, 17:10

BladeRider wrote: ↑08 Apr 2018, 13:27 Thanks for the diagram. Is that relay 2/35? I see no 2/37 and 2/35 - 5 goes to the motor.
I also have the Haynes manual, I'll take a look there if need arises again.
Good to know the starter motors are reliable. I have other things planned, like rear suspension, and a diagnostic tool for SRS before worrying about the starter. At least that's the plan.
Thanks for all your help.

Sorry, fixed it above. 2/35 is the relay

Ive got 200k on my OEM starter and it still spins like new. One key is when you do get a hard start problem, don't overheat it with long cranking. If a Volvo doesn't start in 5 seconds, something is wrong.