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[2001 V70 2.4T] ECM-644A - Camshaft control, faulty position

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prwood
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[2001 V70 2.4T] ECM-644A - Camshaft control, faulty position

Post by prwood »

VIDA has been showing me this code for about a year now. The car still starts and runs normally for the most part, but I do notice that the first time I start it up after the battery has been disconnected, there is some sputtering, as I think the computer must be adjusting to compensate for the condition. City gas mileage also seems to be lower than expected.

The diagnostic info in VIDA for ECM-644A states:
- If all the adaptation values are correct (between -7 and +7), the fault is cured by adjusting the camshaft settings.
- If the adaptation values are -20 or +20 (maximum adaptation), and the camshaft setting has been adjusted, then the camshaft reset valve is defective.
- If any adaptation value is between -20 and -8 or +8 and +20, and the camshaft setting has been adjusted, the variable valve timing unit is defective
I've taken readings at various points along the way:

1/14/2018: between +17.59 and +18.58
( in between these two I had to re-re-do my cam cover seal job, and thus re-set the timing belt again - in previous iterations I think I had incorrectly calibrated the VVT hub which resulted in the really out of what numbers above )
2/6/2018: between -3.75 and -4.80
4/24/2018: between -9.09 and -10.44
10/20/2018: between -8.15 and -9.5

One theory I have is that I'm not tensioning the timing belt correctly, and that the exhaust VVT hub has slipped a bit. I'm thinking that next weekend I may try checking the timing marks, realigning if necessary, removing and reinstalling the timing belt, following the VIDA instructions for my engine. I've seen other different interpretations of this procedure, but I'm thinking I should trust the procedure in VIDA that was generated specifically for my VIN. Would love to know if others have opinions on the VIDA procedure or other thoughts on resolving this ECM code.

For B5244T3, chassis # 077411, engine # 2304894: (keep in mind the procedure is different after engine # 3188688)
1. Turn crankshaft until markings on crankshaft and camshaft pulley correspond.
2. Turn crankshaft a further 1/4 turn clockwise and then turn back until markings correspond.
3. Slacken off belt tensioner center screw.
4. Hold center screw while using 6mm allen wrench to turn tensioner eccentric clockwise to 10 o'clock
5. Remove timing belt (ed: from camshaft gears).
--snip part about completely removing belt--
6. Screw tensioner center screw into place by hand.
7. Ensure that tensioner fork is centered over cylinder block rib, and that allen hole on eccentric is at 10 o'clock
8. Install timing belt over all gears/pulleys. (ed: interesting to note that the VIDA instructions don't explicitly say to hold the spring-loaded exhaust VVT unit in the marked position when installing the belt, I'm just assuming you're supposed to do this since they later have you verify that all markings line up?)
9. Turn crankshaft clockwise until belt is tensioned between intake camshaft pulley, idler pulley, and crankshaft.
(ed: following instructions assume procedure is carried out with cold engine at ambient temp of 68F)
10. Hold center screw on tensioner fixed. Turn the eccentric counter-clockwise until tensioner passes marked position. (ed: i.e. 68F, center position)
11. Then turn eccentric back (ed: i.e. clockwise) so indicator reaches marked position in center of window.
12. Hold eccentric in place and tighten center screw to 20nm.
13. Verify indicator is still in correct position.
14. Press belt (ed: between camshaft pulleys, and between exhaust pulley and water pump) to verify that tensioner arm moves easily.
15. Turn crankshaft twice to verify that markings line up with top timing cover and that crankshaft marking matches up.
16. Check that tensioner indicator is still in marked position.
Cars I've owned:
- 2015 to current: 2001 Volvo V70 2.4T; 2004 Honda Odyssey
- 2007 to 2015: 2002 Subaru Legacy L Wagon
- 2003 to 2016: 2001 Toyota Corolla LE
- 1999 to 2003: 1994 Toyota Camry LE
User avatar
prwood
Posts: 540
Joined: Fri Oct 02, 2015 9:24 am
Year and Model: 2001 V70 2.4T
Location: Salem, Massachusetts, USA
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Re: [2001 V70 2.4T] ECM-644A - Camshaft control, faulty position

Post by prwood »

Bump?
Cars I've owned:
- 2015 to current: 2001 Volvo V70 2.4T; 2004 Honda Odyssey
- 2007 to 2015: 2002 Subaru Legacy L Wagon
- 2003 to 2016: 2001 Toyota Corolla LE
- 1999 to 2003: 1994 Toyota Camry LE
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abscate
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Re: [2001 V70 2.4T] ECM-644A - Camshaft control, faulty position

Post by abscate »

The belt tension isn’t too critical , these belts do not jump time too easily. If the marks lineup, I would guess a faulty CVVt hub

I might have a used one
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prwood
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Re: [2001 V70 2.4T] ECM-644A - Camshaft control, faulty position

Post by prwood »

abscate wrote: Wed Oct 24, 2018 12:08 pm The belt tension isn’t too critical , these belts go t jump time too easily. If the marks lineup, I would guess a faulty CVVt hub

I might have a used one
I'm never convinced that I've gotten the belt tension right, especially when it comes to getting the temperature indicator in the right place. One video I watched said it was "critical" to get the indicator right. I don't know who to believe! I'm actually thinking about making a chart comparing the belt and tensioner install procedure from VIDA, Haynes, FCP Euro, 1A Auto, RobertDIY, and various PDFs I've found here on MVS, just because they don't all seem to agree! :lol: :lol:

Re: The used part. My engine takes part #1275363: https://parts.volvocarslisle.com/p/Volv ... 75363.html

This part # is used on the following models, although there was a chassis# split in the V70 2001 model year (CH -92351. CH -239999. CH -170999.)
Screen Shot 2018-10-24 at 3.05.00 PM.png
Screen Shot 2018-10-24 at 3.05.00 PM.png (126.27 KiB) Viewed 1234 times
I put on a replacement exhaust camshaft last year, but I can't remember if I kept my old VVT hub or used the one from the replacement, and if so, where the other one is... or if it even had the VVT hub on it from the junkyard... *hmm*
Cars I've owned:
- 2015 to current: 2001 Volvo V70 2.4T; 2004 Honda Odyssey
- 2007 to 2015: 2002 Subaru Legacy L Wagon
- 2003 to 2016: 2001 Toyota Corolla LE
- 1999 to 2003: 1994 Toyota Camry LE
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