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2004 V70 2.5T CEM Issue?

Help, Advice, Owners' Discussion and DIY Tutorials on Volvo's stylish, distinctive P2 platform cars sold as model years 2001-2007 (North American market year designations).

2001 - 2007 V70
2001 - 2004 V70 XC (Cross Country)
2004 - 2007 XC70 (Cross Country)
2001 - 2009 S60
2003 - 2007 S60 R
2004 - 2007 V70 R

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rntaboy
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Year and Model: 2004 V70 2.5T
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2004 V70 2.5T CEM Issue?

Post by rntaboy »

My V70 has been having a number of intermittent issues recently. Last week someone scanned it and got these DTCs, but it drove fine:
P2509 ECM/PCM Power Input Signal Intermittent
P203F Reductant Level Too Low
P0562 System Voltage Low

A few days later the vehicle started going into limp mode with limited power and the none of the gauges/lights on the dash cluster working with the exception of the Check Engine light. Reconnecting the battery will typically reset this issue.
When it was scanned after the limp mode began happening, it returned these DTCs:
U0073 Control Module Communication Bus "A" Off
P0503 Vehicle Speed Sensor "A" Intermittent/Erratic/High
P0863 TCM Communication Circuit
P0442 Evaporative Emission System Leak Detected (small leak)

I took it to a shop and they were unable to get the issue to happen in order to diagnose it. With such a random assortment of DTCs, what might be causing this? Is the CEM and/or something else failing?

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br0dy519
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Year and Model: 2004 XC70
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Post by br0dy519 »

How old is your battery and have you tried a few load tests on it?
04s60 2.4
04xc70 2.5t
prwood wrote:I wish I had a permanent car repair area that was covered, had a level surface, lighting and fans, a workbench, and tool cabinets. You know,like a garage. Much of my time during the job is spent hauling things up and down the stairs to the basement or in and out of the storage shed, or running back downstairs when I realize I need something else,or taking a break from standing out in the sun,or using flashlights or work lamps when it gets dark.

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packetfire
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Post by packetfire »

This is a dead giveaway - P0562 System Voltage Low

That code means that your battery dropped down to LESS than 10 volts!

You can't expect the eleventy-seven computers to work in a Volvo with a crap battery.
When running VIDA, most of us both connect a battery maintainer to the Volvo's battery, and run the DiCE on its own 12-volt power brick for all but a brief scan and go.
1982 240DL: Drove it 32 years and 1.5 million miles (sold, even still had mint leather!)
2001 v70 2.4T: The most expensive $1500 car I ever bought ("Volvo Turbo" - what an oxymoron!) (sold)
2004 v70: Far less fatally-flawed v70 - It served well (sold)
2010 v50: Smaller, slightly sportier wagon. Its got a spoiler, so I upgraded with sway bars!

rntaboy
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Year and Model: 2004 V70 2.5T
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Post by rntaboy »

To clarify my initial post, the first set of DTCs are no longer showing up. They were replaced by the second set. So when it went into Limp Mode it was no longer giving a P0562 System Voltage Low code, just:
U0073 Control Module Communication Bus "A" Off
P0503 Vehicle Speed Sensor "A" Intermittent/Erratic/High
P0863 TCM Communication Circuit
P0442 Evaporative Emission System Leak Detected (small leak)

I'll definitely get the battery tested, but considering that System Voltage Low code isn't coming back now, is there anything else I should take a look at?

motormikeyman
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Year and Model: 2004 XC70 AWD
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Post by motormikeyman »

It could be a CEM or DIM issue for sure. You can narrow it down with this diagnostic flowchart from Xemodex:

https://xemodex.com/us/dim-cem-low-spee ... flowchart/
'94 940 wagon, 220K miles- sold to a guy who then drove it to Oklahoma
'99 XC70 AWD, 210K miles- trans went
'04 XC70 AWD, 196K miles- still going strong
'06 S40 sedan, 150K miles- went with the ex

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