CAT warning light

[alay111]

The water pump seized and then blew up at 100kph. Then an almighty bang from the engine bay as the water pump disintegrated and broke the shaft and the water pump pulley disappeared somewhere into the night. As I pulled over the dash had lit up like a xmas tree. I have now replaced the pulley and water pump and restarted the engine but the CAT light remains on (the bottom left light in the instrument display panel). Can anyone tell me what this is for? I've spent a lot of time looking and can't find any reference for it and the owners manual I had purchased off ebay either isn't for a Mk1 Sharan or has the information missing.

[johnnyroper]

By cat warning light do you mean the engine management light? (Orange engine shape) or is it a different light?

[alay111]

It is not the standard engine monitoring light ie a picture of an engine. It is in red and says CAT

[insanitybeard]

It's a new one on me, are you able to post a picture of your instrument cluster showing the lamp illuminated and it's location on the cluster?

[johnnyroper]

Not seen one like that before all I can assume is it has detected a discrepancy between pre and post cat O2 readings? As it happened after pump failure is it possible the pulley being ejected caught wiring or plug for one of the sensors?

[alay111]

The battery is out at the moment getting recharged so will post a picture tomorrow. I also have a Mk1 Galaxy and that doesn't have the warning light (according to a manual I found on line) and my recollection of the panel (it's been 4 years since I last drove it).
I don't think it is related to the catalytic system because the drive belt once failed on me a few years ago and this light came on then so I believe it is drive belt related, if that helps at all.

[insanitybeard]

Unless it's related to the secondary air pump, IIRC the VR6 engine has one of those fitted for emissions purposes, not sure if it's belt driven though.

[johnnyroper]

Very odd fault,I would see what happens when you put battery back on as being off may have reset it.

[alay111]

Maybe should have mentioned this before, the light comes on every time you turn the ignition on eg like the oil pressure light, battery light, abs light etc. Start the engine and then after a second or so the lights turn off including this CAT one, but this time it hasn't.

[insanitybeard]

IIRC the secondary air pump blasts air into the exhaust manifold to improve emissions on a cold engine before the catalyst is up to normal operating temperature, therefore if the pump or associated piping/ wiring has been damaged by the pulley flying off into the engine bay it could be a possible cause.

However, it's not clear from the parts diagram what powers the pump, I'm guessing it may be electrically as opposed to belt driven.

[alay111]

There isn't anything unusual on the belt run - crank, air con, power steering, alternator, tensioner and water pump. Unless it runs off either the power steering or the aircon then I'm at a loss. I spent half an hour checking to see if anything was damaged before I fitted the water pump, I'll have another long look later today and see if anything is out of place but the way the engine sits up against the side of the bay means there is very little the pulley could have done other than fall to the ground past the crank and steering pump pulleys.

[johnnyroper]

The secondary air pumps are usually electronically controlled via the engine ecu,well if it's same as the ones Vauxhall used to use. Once ecu sees a rise in running temp it shuts the air pump off.

See if ecu resets after battery is refitted if not then a diagnostic plug in should point you in right direction.

[alay111]

Still don't know what it is but it is definitely electrical related. Alternator has now gone awol, 0 output and after pulling it out and apart, it is well stuffed and for a vehicle that has only done 100k I'm surprised. Will pull the one from my galaxy and then mull over a rebuild. Photo attached of instrument panel.

[johnnyroper]

Never seen that light before, vcds scan way forward for that one I reckon.

To be fair alternators can go anytime it's just one of those things,I have known them fail well inside manufactures warranty at less than 20k.

[KingyMAK]

None of the uk models had the cat light; I'm sure it's Euro and American specs only, as it was the same with the Golf.
It's an o2 sensor wire at fault from what I'm aware of, but a scan via VCDS would help.

[insanitybeard]

Ah yes, and looking more closely at the cluster picture (something I didn't do first time round), it's a km/h speedo so not a uk market model. Not sure if the O.P will see this now but just in case do you know which country it was originally sold in, and is it left or right hand drive?

Edit: O.P's email ends in nz so possibly New Zealand?