1GGTE Diagnostic

[beterthenu]

Hey,
I'm having issues with my 1GGTE, where, if the car comes close to being on boost, I loose a considerable amount of power and the check engine light comes on. I'm guessing it may the MAF sensor but I am not sure as I cant work out how to get the error codes out of it. Every article I read, advising me to for example “bridge TE1 and E1, turn on the ignition and watch the CEL”, I am unable to complete. Mainly because there is no TE1.
My diagnostic plug does not appear to be the same as previous posts on this subject.
Would anyone have any insight as to how I pull the error codes out of my ECU?

Thanks,
Lachlan

[yotamotion]

What shape is the diag plug, round or square? If there is a T1 pin use that one. Also, I had what sounds like the same problem , with check engine light coming on as well, and it turned out to be a loose hoseclamp on one of the intake pipes.

[beterthenu]

Its square. So would that be bridge T1 and E1? My car is stuck at work at the moment so I cant check exactly what pins there are.
Is spraying aerostart around the engine bay and listening for increased idle still the best method for finding leaks?

[yotamotion]

If you want pm me your email address and i can send you a picture of which pins to short out. As for finding leaks that way I dont know I just went over all the clamps with a socket. Also, check that there are no cracks in the rubber hoses, they can deteriorate and crack apart around the hose clamps, especially the ones mounted to the turbo.

[yotamotion]

Better still how about I post it here forgot I could do that. Is this the plug you have? If not T1 and E1are the terminals to short

[beterthenu]

Sweet, thanks for that. Once i get back to my car i will give it a go and let you know how i went.
Cheers,
Lachlan.

[beterthenu]

Right, first off, I have to say, never assume that because you buy a car off a fellow toymods member, that they are honest. It turns out there are multiple issues.
First, finally worked out why I could pull error codes from the ECU, the previous owner/builder had cut the TE1 wire at the ECU. Upon connecting the wire, and bridging E1 and TE1, the CEL began flashing when the ignition was turned on. I then disconnected the bridge and went to take the car for a drive to produce the error, as I had reset the ECU when checking connections. I turned the car on and the CEL continued to flash, even tho the bridge was removed. Obviously he had just cut the wire to stop the CEL flashing, rather than diagnosing the issue. Which poses my next issue, why is the CEL constantly flashing? I checked resistance between E1 and TE1 to check for shorts in the loom, which didn’t result in a short. I also checked for a ground short from TE1 to ground, which also proved negative. Anyone have any idea what’s happening here?

I managed to take the car for a drive to reproduce the error, which resulted in error code 52 – knock sensor. I then proceeded to check the knock sensors, only to find one was missing??? The wiring for the sensors has also been butchered with twist and tape jobs. The whole car is done with twist and tape jobs.
Any ideas how the car was running with only 1 knock sensor? Why would he remove one sensor?

Any help would be greatly appreciated, especially if there is someone in Brisbane who knows these motors who’s willing to lend a hand.

Thanks,
Lachlan.

[beterthenu]

Just had another look, he has joined the knock sensor wire to the missing sensors plug.
What should I do?

[thechuckster]

you have to remove power to the ECU for a while to reset any codes - disconnect the battery for 20 secs should do that - then see what errors it produces after starting up - the CEL light should come on with ignition on but engine not turning.

i probably have a spare sensor attached to my 1G block

engine will run with 1 knock sensor - it's only used for retarding timing when it senses knocking under load and cruise - just run PuLP if you're concerned.

when you say 'joined' do you mean the core of that wire is connected to the shield? or to another trace? Just makes sure the knock-sensor wire does NOT connect to the shield or earth or any other wire.

In my loom (gen 2 i think), the two knock sensors actually connected to one pin on the ECU - so if one was disconnected and as along as it wasn't shorted out, it would still knock sense.

[TA-022]

there are two style plugs for the knock sensors ... a square and round 1. Make sure you get the right plug to go with the sensor you put in ... i had to replug mine to suit the sensors i had.

[beterthenu]

Hey,
Yes, I am aware of how to reset the ECU. As stated before, the issue I had with getting the error codes from the ECU is that the previous owner had cut the TE1 wire at the ECU end. When I reconnected the cut wire, the CEL does not stay steady on when the car is ON, rather it flashes as if E1 and TE1 were bridged even tho they are not bridged. However, I tested both TE1 and E1 for a ground short with no result.
How is this possible?

He had joined the cores of both knock sensor wires and plugged it into one knock sensor. Depending on how the ECU is designed, I could imagine this could have very unexpected results? I have since removed the link between them and corrected any shield shorting.
Edit: thechuckster – I think this may be the configuration on my ECU as well, as I believe the o2 sensor should be a shielded wire too and I only see two shielded wires going to the ECU, therefore it may only use one wire for both knock sensors. The previous owner clearly had no idea what he was doing with electronics.

Since then, the flash of the CEL has become very erratic.

The latest code from the ECU is 51 - Switch signal - “Air conditioning switch on or gear selector not in N or Pk during diagnostic check”
The car is a manual with no aircon, so I'm not sure what this code is referring to.

I only run the car on BP Ultimate.

The knock sensors are the round connector type.

Thanks,
Lachlan.

[TA-022]

not in N or P ... auto ecu? might have to bridge the neautral start switch to make it think its in neutral then get you CEL codes?.

[thechuckster]

if the wiring is generally dodgy, then i'd first check (and improve) any earths ... 99% of electrical issues are ususally mechanical (e.g. poor connection) or bad earths...

[beterthenu]

I am now completely at a loss. I have no idea what's wrong with the car. Does anyone know of anyone good who I can take my car to in Brisbane?
It’s a TA23 with a 1GGTE.

Thanks,
Lachlan.

[beterthenu]

Getting back to my odd issue with the cut T wire. To recap, the previous owner had cut the T wire at the ECU. See diagram –



My question is, why does my CEL flash as if the test terminals are bridged, when they are not. I have checked for a short, and cannot find one. If I cut the wire again, the CEL resumes normal operation.
Any ideas?
Lachlan.