Hi all;

Does anyone know where this sensor is? Apparently if it malfunctions or if the connections are a bit dodgy it causes the car to run in emergency mode ... which is the problem that I seem to have.

Thanks.

You sure its faulty and not just doing the job its supposed to????

do an ecu diagnostic check - code 34 means a bad det sensor/wiring

What is it supposed to do? I think I'm clutching at straws, the ASCD fuse keeps blowing and putting me into emergency mode so I would like to check the connections to it so that I can eliminate it if it's not the problem ... I hate bloody auto-electrics!!!

The sensor is down between the V of the engine. Nightmare to get to the actual sensor as you have to take the whole top off eg all pipes ,plenum, fuel rail (if i remember right), etc. The wire from it comes out the back near the egr area and plugs into the main loom there (same part of the loom that the coils plug into).

Can't see what its got to do with ascd fuse though. The cruise control has been taken out of my car, along with the aircon, and other bits. Runs absolutely sweet. Lots less to go wrong.

Dave

http://zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html

Hi all;

Does anyone know where this sensor is? Apparently if it malfunctions or if the connections are a bit dodgy it causes the car to run in emergency mode ... which is the problem that I seem to have.

Thanks.

 

when i initially got my zed i had a dodgy sensor that had "melted" due to the engine overheating when the headgasket blew.

 

rather than having all the top of the engine (pipes / plenum etc) being removed, this sensor was relocated to a much easier place to gain access to.

 

may be worth looking into if it does need fixing?

Thanks guys ... I will check what I can, although I agree that it is probably not the source of my problem but I'm willing to try anything.

Thanks again.

is ASCD for the cruise control? is so, the wee vacuum pump beside the cruise control actuator might have siezed so its pulling high current? it wont pull anymore than a few amps so if its a big fuse its unlikely thats the problem. There is very few parts other than the pump that would cause the circuit to pull high amps as surely its mostly software controled with a setpoint for the current speed and measured value from the speed or rpm sensor and an output to the pump. have you looked for chaffed wiring and poor insulation? it might be shorting to earth.

I dont think the Det. sensor will help you, it gets fed 4.5V directly from the ecu and back to earth, i dont think it goes through a fuse.

Touch wood i havn't had any bother with the HICAS or Cruise Control, so im only throwing logical ideas at you.

good luck,

Fraser

Thanks Fraser I will check it out ... just need to find it first but your suggestion sounds logical. I'm suffering from a torn lumbar disc at the moment so I'm not going to hop out and sort it right now but I'll let you know how I get on. If the pump has seized any ideas on how to fix or replace it?

Thanks again.

Terry

pump is right beside the actuator on the very top of the engine. if you follow the second throttle cable out from the throttle bar at the front (its about 8" long) it goes in to a oval black box, theres a short rubber hose coming out and it goes to a wee pump unit about the size of your fist.

I have to say, after i posted my first reply, i looked throught your previous post a few pages back. i see its a 10A fuse! thats quite a lot of juice!

does this happen all the time or just when the cruise control is on? cos i would have thought the pump would only come on when the cruise control is switched on.

had the engine out or done any digging aroung the engine bay? a connector might have snapped and shorted out or wire might be pinched.

It happens all of the time now, I can go for a few miles and then the fuse blows. I don't use the cruise control so it's not the switching that does it. I did take out the ASCD Cancel relay and it was fine for about 3 months but now it blows the fuse wheter or not the relay is in or out. I had a major auto-box job done earlier this year and all was OK until I took it back for the first service and it blew on the test run. As they only changed the oil on the service they felt it was nothing that they had changed or touched. They did have the car for a few days but couldn't find the problem and suggested that I give it to an auto-electrician ... I don't know any who would be au-fait with a ZX! There must be something on this circuit that is shorting somewhere. These problems are always obvious when you have found them ... but it's finding it in the first place!!!!

Thanks again.

have you done an autobox diag, or a hicas diag? these systems are kind of inter linked with the speed sensors and stuff. you might get lucky. the links are on here somewhere if you havn't done it before. seems funny how it was fine until the g/box was played with.

i dont know if theres a diag for ASCD? theres one for everything else, even the climate control!

I did the auto diagnostics and it was fine ... all 10 blips the same (with a good fuse in the ASCD). It would not perform the diagnostics with the blow fuse. I haven't ventured as far as any other diagnostic checks, I thought the auto one would have been the obvious one to do, I will have a go later though.

It seems it is common to go into safety boost in hot weather as the det sensor is actually sensing detonation as it should.

 

I have had this on a stock engine when the ambient temp gets to 28 or above. I normally use regular unleaded fuel (UK car is OK on 95 RON) but running on Optimax during the summer solved it totally :hyper:

 

Richard :smw:

Thanks Richard but this first started in Feb/March when it was a lot colder. The main problem is that the 10A ASCD fuse keeps blowing and then only allows emergency mode.

Terry.

does this help?

 

http://www.twinturbo.net/ttnetfaq/FAQpages/ascd.html

Thanks Fraser ... now some of that does make sense especially the stop lamp circuit and also that the back-up lights amy also be on the same fuse.

Thanks again, you have been a tremendous help and I'll have a look over the weekend and I'll let you know.

Terry.

SOLVED!!!

Would you believe it? I took the car to a local Auto Electricians ... CPC Autoelectrics, Telford, told them the symptoms and gave then the workshop manual on a CD not believing that they would be able to help. They eventually found a wire that was touching the exhaust pipe which was part of the right circuit, repaired it and hey presto everything seems to working fine again. It took them about 3 hours, cost me £140 but worth it.

They seem to think that the wire was probably moved out of the way when the gearbox was being sorted and then forgotten about.

Anyway, thanks folks for all of your help and suggestions ... most of which I tried to no avail, even taking off the fascia etc (what a bloody mess of wires under there!!!) but now my aircon blows where it should.

Terry Davies

good stuff! glad its fine now

Money well spent then.