ALDL Help no +12V

[simc]

Hi all,
I have been trying to get the ALDL port working on my Holden VP engine with no luck. I have confirmed the pins and construction of my ALDL cable a number of times, and installed various transistors.

I did some testing on the ALDL plug from the ECM and there is only 3.5V from what I think is meant to be the 12V line. (Top left pin)

Also, with a 10K load in place on the ALDL port, I dont get much happening on the data toggle line, 40mV constant, and 8mV without the 10K load.

Even using a 12V source from the car, WINALDL still does not detect.

I need to get this working so I can finish the tune on my car, any help would be great!!

[delcowizzid]

you need a working check engine light to connect if it isnt working you wont get aldl data .the CES light has power through it to the aldl plug and ecu the cable for winaldl is detecting the 12v being earthed out to get its data

[simc]

Thanks for that delcowized, looks like you are right on the money!

I was aware that the CEL was not connected as I have a grey wire free coming off the Warn LP relay, so I will connect that to a light. However I had a closer inspection and noticed a (Brown/White) wire off the ALDL port not connected which looks to be essential, and probably the big issue.

Any idea where this is meant to go to?

The wire comes from the back of the ALDL connector, runs down to another connector which has the transmission signal cables. The wire is then cut off and not connected to anything. On this same connector, there are two (Brown/White) wires, with the second (Brown/White) wire also cut off /not connected running back to the ECU.

Is this meant to be a loop? Should I just connect the two cut wires together?

The two sets service manuals I have contradict themselves and are not much help in this area.

[delcowizzid]

brown and white from aldl plug to a junction then one goes to A5 on the ecu plugs other one tees off to the check engine light globe. the globe has 12v switched ignition power going in when ignition is on and goes out the brown and white to the ecu to be turned on vis the ecu earthing it.you can cheat if the brown and white is in tact from aldl plug to ecu just put a test lamp lead in the aldl plug where data comes out then with the other end to 12v and she will work

[simc]

Worked like a charm! *Pats delcowizzd on the back* woo hoo now to continue the tuning

Win ALDL reported 44 lean mix. However the car is still busy puffing out black smoke on idle, and feel rich when driving (splutters). Im guessing its still the original O2 sensor, so ill grab a new one and give that a shot. Do most people use winaldl or is there somthing better out there?

Any tips for an ideal AFR on a 7PSI intercooled V6 13-14?

[vn5000]

Good to here you got it going.
win aldl was great in its day , but tunerpro 4 or 5 makes it look anciant.

[Jayme]

hang on a tic... this motor is running boost? with a 5D? do you have a 2 bar map sensor? or a rising rate reg?

[delcowizzid]

any psi you want to be in the 12's:1 could get away with 12.5 for max power higher boost down in the 11-10 range on accel

[simc]

Yeah its running a 3.8L V6, 2bar map, with a 2 bar tune. Also running 36Lb injectors, intercooler all jammed into a gemini. At the moment its running ok. Idles a little rich and it feels rich while driving. I am running a tune from a 12 psi car, but have it down at 7 psi, so on the first drive, she was running very very rich. I backed off the fuel and after 5 tunes it got progressively better, but being a first timer, I wanted to get some monitoring setup before I got too lean etc.

According to what I have seen, an AFR of about 12-13 translates to 0.8-0.9V on the 02 sensor output, sound about right?

Also, with winaldl logging engine knock counts, I’m assuming I can use this to establish the borderline timing for the engine. ie. Advance until there is a knock count, and then back it off a couple of degrees.

[Holden202T]

13:1 afr is pretty close to 800mv and 12:1 would be getting towards 900mv .... atleast if your in that range its probably not going to damage too much .... but if your using the narrowband to log this on boost i'd be leaning towards 900mv to be safe!