CAS issues. (updated)

[mic*]

My 1GGZE is throwing a code 12 and wont start. Me thinks this is RPM signal - ie CAS?

Anyone know what to do next? Ie testing it electrically. Possible causes of / testing for mechanical failure of CAS?

I cant find a wiring diagram for a waste spark (gen3?) setup, only gte distributor diagrams...

Thanx in advance

[brett_celicacoupe]

something simple i can think of doing is checking the resistance of the CAS pickup.

ill bet its the same specs as the 7MGTE CAS in the supra TSRM floating around (URL cygnus.net.somthing?)

[FASTFOO]

Code 12 is the crank angle signl to the computer down the "NE" wire.
So check continuaty between the red wire coming out of the CAS and NE at the computer and continuaty between the white wire at the CAS and G- at the computer (do this with the computer and CAS unpluged)
if the wires are good and go where they are ment to then put your multi-meter on to the lowest volt setting and then test for small voltage spikes when on NE and G- when you turn the CAS slowly.
MATT.
Hope this helps.

[mic*]

Thanx for the help ppl.

I have checked continuity of the harness from CAS clip to ECU clip, for all four wires. All OK.

I have checked the CAS with a multimeter (on 2000mVDC setting) between G- & NE. It gives little spikes as you turn it. Incidently, i tested each wire against every other wire and there is small voltage spikes with every combination.

I tested for resistance across wires of the CAS and found that the resistance between the NE wire and any other (G-, G1, or G2) was ~175ohms. The resistance between any other pair of G-, G1 or G2 was ~350ohms... This means very little to me tho, except that it would seem OK?

So i still have nothing to blame...

[FASTFOO]

Check continuity with plugs disconected because as you have foud out they all join through the CAS and the computer.and will always get continuity.
With CAS unplugd check for pulse between ne and g- that is the one the code is for.
If all looks good then i would plug it all back in turn the ignition on and turn the CAS. Then test for spark and injector pulse. If there is no spark or injector pulse then you may have a faulty computer (very very rare) and need it repaired or replaced.

MATT.

P.S. should be a fairly easy ECU fix as the fault should be on the NE track.
I used auto service solutions for my ECU work (had to hold there hand a bit) but I belive "sideshow" will do this to and from what I read he could do it with his eyes closed.

[mic*]

Thanx heaps ay...

I did test the harness with the ECU and sensor unplugged. Similarly i checked for voltage spikes with the sensor pulled completly out, disconnected etc...

When its all in, the engine does not get fuel or spark when cranking. Feels dead... But i thought this would be normal if the ECU has no sense of engine position? Does code 12 cover engine position sense & rpm sense when they are both the same sensor, or does the code specifically narrow it down to the rpm sense - NE?

[DX20VT]

I have checked the CAS with a multimeter (on 2000mVDC setting) between G- & NE. It ?

Try it on 20 V AC. you will gat a much more readable reading. The faster you spin it the more voltage. Much easier to tell.

[mic*]

Try it on 20 V AC. you will gat a much more readable reading. The faster you spin it the more voltage. Much easier to tell.

On 200VAC setting it makes up to 9V at the rate i can spin it by hand. For the record all four wires to the ECU measured up at <2ohms.

Seems like it should be OK???

Cant understand why the ECU would just shit itself I guess it must happen tho

Glen... Where are you? Mind if i come check my ECU on your GZE?

[mic*]

I have tested the ECU now and its fine. Since everything seems ok, today i clipped the CAS & ECU back in, then turned the key to "ON" and manually turned the CAS while i had a spark plug resting on the head.

Low and behold, good clean spark, and since it was dead quiet, i could also hear the injectors firing.

So im thinking that maybe the error code (12) has just led me up the garden path for a fueling prob - pump, regulator, blocked filter... Any thoughts?

Also, could someone please confirm that the picture below shows the position the sensor should be at when the engine is no.1 cyl @ TDC. If not, how many degrees out is the picture?

[mic*]

bump bump.

[thechuckster]

only a guess ... the 7mgte cas is similar so on a hunch i'm going to suggest that the TSRM for the Mk2/3 supra will show how to position/time the sensor accordingly.

Search for TSRM and Cygnus as i donlt have the URL on my work PC.

[mic*]

http://www.supra.co.nz/87tsrm/

Thanks Chuck

[FASTFOO]

On the other end of the CAS where the gear is there is a dot on one of the teeth and you line it up with a groove on the housing.
same as on 7m's and 4AGE's.
Have them lined up as you slide it back into the head, dont worrie that it turns a bit as it hits the bottom.
MATT.

P.S. Just a thought but how is your starter motor because you can get a code 12 if you try to start the car but the engine does not crank.
(computer gets an "STA" signel and expects an "NE" signel that it will not get if the engine not turn. Just a thought.

sound like fuel pressure might be next check.

OH and another thought has it broken a timing belt (hence start signel but crank signel) I remember a few years ago we spent a day and a 1/2 checking every wire in a loom we just made because the engine we tested it on had a broken timing belt
BEST OF LUCK

[DX20VT]

On the other end of the CAS where the gear is there is a dot on one of the teeth and you line it up with a groove on the housing.
same as on 7m's and 4AGE's.
Have them lined up as you slide it back into the head, dont worrie that it turns a bit as it hits the bottom.
MATT.

like this,