2000 S70 CEL P1670 P1671 Failed smog test functional

[fars70]

Hello,

My Volvo S70 failed to pass smog test (the functional portion) because of a couple check engine lights. Not to long ago the Coolant Expansion Tank, 02 Sensors, the Radiator had to be replaced. So when the mechanic said it would cost about a grand to fix, it felt like more money into the pit. Hopefully I can fix it on my own, with the forum's help of course. The functional portion failure, was due to CEL codes p1671 and p1670. i believe p1671 stands for too high/ too low signal to the cam position sensor and p1670 is an immobilizer issue.

I'd like to start with the 1671 first because I already bought a used part off ebay, but I'm having trouble taking out camshaft position sensor. The top portion (kind of looks like a pellet) had an accessible screw which I removed, but when I tried following the wire it seems the connector goes into the engine making it unreachable. I'll attach some pictures. Thanks for the help.

Oh and I found this link, the fourth to last post with the pictures is what I refer to as the camshaft position sensor pn# 9202134. https://www.matthewsvolvosite.com/forums ... =1&t=24922

[VCA]

The instructions in VIDA say to "expose the wiring", I've attached the diagram in case it helps you. Make sure you use a new gasket, and tighten that bolt back to 17Nm (12.5 lb-ft).

For your P1670, look up S70 antenna ring on this site to get some tips for cleaning the contacts, or, if necessary, replacing the antenna.

[fars70]

Thanks for the picture. I am a bit of a novice, which gasket are you referring to? Is the gasket, the 'camshaft solenoid gasket' p/n 30731212? And to expose the wires, looks like I have to pull it until I see the connector or do I need to cut the wires to get it out? I'm attempting this all from the driver's side, could I move anything to facilitate ease of access?

Sorry for the troubles.

[VCA]

Sorry for the confusion on the gasket, my coffee hadn't kicked in when I typed that, sorry! It's strongly recommended you use a new throttle body gasket since you had to pull it to do the repair, it's part 8636753, $4.

The connectors are there, you should trace the CMP sensor cable back, remove any electrical tape bundling it with other wires/split loom, and you will find the connectors roughly between the intake manifold and the engine block. There's a post on VS for the 850 that shows the vicinity: http://volvospeed.com/vs_forum/topic/15 ... 999-v70xc/

[fars70]

Okay. It's a bit more involved than the "remove the two bolts" I've been hearing, I'll order the part part in the mean time. Thanks again!

[fars70]

Hello,

Is the attached picture, the throttle body gasket? Now the hard part after getting it un-clipped, will be freeing the connector because it's so tight to the engine. Still waiting for the gasket, but if this does not solve the 1671 code, what else could it be? Thanks.

3/15/14
Is the part number for the immobilizer 9442961? And stupid question, but very important: Do I need to disconnect the battery?

http://volvospeed.com/vs_forum/topic/56 ... placement/ If anyone else needs help with the immobilizer there's a diagram.

[fars70]

So I switched out the CPS with the used one from ebay. And did the lock/ un-lock doors for about six times to clear the p1670. Cleared the codes with the obd2 reader, went to re-scan, p1670 is gone but my p1671 fault and p1671 pending remain. Do I need to drive the car 100 miles, buy a "new" CPS, or try replacing the vvt solenoid?

[VCA]

Cleared the codes with the obd2 reader, went to re-scan, p1670 is gone but my p1671 fault and p1671 pending remain. Do I need to drive the car 100 miles, buy a "new" CPS, or try replacing the vvt solenoid?

First, congrats on the successful replacement of your CMP sensor! Since the fault came back immediately, it's probably the VVT solenoid. I've attached the diagnostic trouble code information for ECM-6400 (the code that P1671 represents), so you can get an idea of what to look for. Unfortunately without VIDA we can't tell if it's signal too high or too low...

[fars70]

First, congrats on the successful replacement of your CMP sensor! Since the fault came back immediately, it's probably the VVT solenoid. I've attached the diagnostic trouble code information for ECM-6400 (the code that P1671 represents), so you can get an idea of what to look for. Unfortunately without VIDA we can't tell if it's signal too high or too low...

Thanks. Does it mean its pointless to replace the vvt solenoid p/n 1275578 if I don't know if the signal is high/ low (because it can mean other things)? And where is the location of the camshaft solenoid (a diagram would be much appreciated). Should I try cleaning/ fixing it or just buy a new one. Decisions, decisions...

I'm pretty sure the CPS i bought off ebay was in working condition (if the listing don't lie), but what's the best way to test a CPS? I saw no signs of corrosion nor missing pins in my old one.

[VCA]

Thanks. Does it mean its pointless to replace the vvt solenoid p/n 1275578 if I don't know if the signal is high/ low (because it can mean other things)? And where is the location of the camshaft solenoid (a diagram would be much appreciated). Should I try cleaning/ fixing it or just buy a new one. Decisions, decisions...

I've attached a repair description for the VVT solenoid. For the CPS, it's a hall effect sensor, so testing it without an oscilloscope isn't really do-able to my knowledge. You may want to remove the VVT solenoid and see if there's any sludge in the channels. If it's pretty clean, it's likely the solenoid (ohm it out, it should be between 3.7 and 11.1 ohms. There is a new solenoid design (36002696 for the kit including new solenoid, gasket and screw) which is supposed to alleviate some of these problems.