Robbo149 0 Posted July 16, 2004 Hi all, I've replaced my CPS 3 times now & still get an error code on diagnostic, the car is running as it should with the CPS out (crap!). (I've reset the ECU each time btw) Is there any other way to check the sensor & its wiring to find where the fault lies? Cheers, Robbo Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 16, 2004 Hi all, I've replaced my CPS 3 times now & still get an error code on diagnostic, the car is running as it should with the CPS out (crap!). (I've reset the ECU each time btw) Is there any other way to check the sensor & its wiring to find where the fault lies? Cheers, Robbo What error code are you getting? You'll need to do an end-to-end wiring continuity test from the sensor plug to the ECU plug. A simple battery and LED will do the trick. This is assuming of course that the cam sensor trigger wheel is all present and correct. It should be on the ABV as it's just a metal protusion on the exhaust cam, but I know VW were pissing about with silly clip on ones prior to 94, IIRC? Quote Share this post Link to post Share on other sites
dinkus 10 Posted July 16, 2004 It's not because the engine isn't running when you ask VAG-COM, kevhaywire seemed to suggest if the engine was off VAG-COM would always throw a code? Quote Share this post Link to post Share on other sites
Guest Posted July 16, 2004 It should be on the ABV as it's just a metal protusion on the exhaust cam, but I know VW were p***ing about with silly clip on ones prior to 94, IIRC? Exhaust Cam? You mean the rear cam. It may say DOHC on the engine cover but it's not the same as a 4V / cylinder engine. Two banks of 3 cyls, 1 cam each, front & rear. The VAG-COM code thrown when the engine isn't running is the Engine Speed Sensor - which clearly doesn't produce a signal when the engine isn't running. It disappears when you start up. The CPS power comes from the injector 12V rail and runs under the coil pack - if you've had the coil pack or thermostat housing off, you may have trapped the wire in the bolts and shorted it to the block (especially if that great cable wrap VW used has dried out and flaked away). Get a Bentley and/or a Russek manual - the wiring diagrams alone are worth it. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 16, 2004 Yeah sorry, rear cam. Still can't get 16Vs out of my head having had them for donkeys years. Both the engine speed and vehicle speed sensors come up on VAG-COM when the engine is off because the ECU is not programmed to detect if the engine is running or not. Quote Share this post Link to post Share on other sites
Robbo149 0 Posted July 16, 2004 Cheers for the replies guys. The original 2.9 cams were swapped over (with sprockets) when I had the recon head fitted, so the trigger wheel (or whatever) should be there as before. I did try to see through the hole using a torch last time I changed the cps, but couldn't see much. Is there any easy way to get at the cam sprockets without having to take the manifold & all the covers off? I'm thinking most likely a wiring problem, I have had a new coil pack on recently, & I've also had a load of electrical problems which were sourced to some of the contacts in the big round multi plug being fooked. Does the cps wiring go through this too? Cheers, Robbo Quote Share this post Link to post Share on other sites
Robbo149 0 Posted July 16, 2004 Sorry guys, forgot to add... the error code is definitely a Hall Sender error (on Bosch diagnostic machine) Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted July 16, 2004 Yep the CPS loom will be terminated at the large multipin connector you describe. I agree, it is almost certainly a wiring issue, I was just trying to cover all possibilities! Quote Share this post Link to post Share on other sites
Rpmayne 0 Posted July 19, 2004 The engine in mines a '94 ABV and I've got the black clip on pickup for the cam position sensor. Can see it when the sensor is removed, and has got a crack across it as it happens. Maybe yours is missing Robbo so the sensor has nothing to pick up on. Hoping mine is going to stay where it is for a while, and not get stuck under a cam or something stupid. :( Quote Share this post Link to post Share on other sites
