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I am trying to locate the VIP Test Connector?? On the electrical schematic it shows this, with a gray wire with a red stripe, that I believe is the signal wire for several sensors,e.g. oxygen,TPS, air charge,EGR, but I can't locate it. I am also wondering what this does?? Is this a connector where you can test these various sensors from one location somehow??
This is called the self test output connector. The other connector needed to get codes is the self test input. It has a wht-red striped wire, right next to sto connector. Mine is on the drivers side fender, under the hood. See fordfuelinjection.com who to read self codes.
In the Chilton manual in the chassis electrical section, 6-67, Fig. 122 is where they show this VIP test connector. Bottom half of the schematic on the left hand side. I have an Autoxray 6000 reader, but I am not trying to read the codes. I am wondering what this VIP test connector is used for and where it is located?? If this is the same as what you are calling the self test output connector, gray wire w/ red stripe, what is it for?? This gray w/ red stripe wire runs to the EGR VPS, MAP sensor, TPS, Air Charge Temp. sensor, Engine Coolant sensor and the Knock sensor, all originating from the VIP test connector. This gray w/ red stripe wire would appear to be the signal wire since all these sensors feed back to the ECM with other wiring apparently for the power and ground??Thanks for the link to fordfuelinjection.
For the 5.0 engine Pin 46 is the sig rtn for all sensors i think it's a little bit like a ground. I think it has less then a volt at the sig rtn's on your size engine. In my Haines manual this is what they call it S.T.O. connector. I think this is want FTE members call it to. I would think this is how the code reader can test for the signal returns for each sensor. Sorry thats all I know. I think my eec is bad because my sin rtn had 5.8 volts which is way to high. Still working on it so its still up in the air. 1987 f150 4.9 efi 2 wheel drive
The schematics for my truck (1991 5.0L), available on alldatadiy.com, also show a "VIP test connector".
But if I look at what signals go there, I find:
Data+
Data-
STI
STO
FP
SIGRTN
These are the same signals that the Probst schematic shows as going to what it calls the "Self Test" connector or "data link" connector. This is the 6 pin + 1 pin pair of spade connectors at the left side of the engine compartment -- STI being the signal you use to pull codes.
The grey with red wire on the alldata schematic is SIGRTN, which acts as a noise-free ground path for most of the sensors. It actually originates at the PCM, but also goes to the "Self Test" connector in the Probst schematic and the "VIP test connector" in the alldatadiy schematic.
It appears that "VIP test connector" is just a synonyn for "Self test connector" or ALDL connector. Supporting this somewhat, is the anecdote reported in the following "Motor age" article (wherein the author describes connecting a scanner to the "VIP test connector")
What are the Data + and Data - wires? I seem to remember something about that, maybe from my Chilton manual or something. I don't know what they would be used for, unless they connect to a Ford diagnostic machine.
Thanks guys -
I knew someone out there would know for sure what this was. In the schematic it appeared to be on the passenger side of the engine compartment rather than the drivers side. Thats what made me think it was an additional connection.
Some of the EEC-IV PCM's had a real-time datalog capability, similar to the OBD-II diagnostic frames. I believe DATA+ and DATA- are used to dump out this data stream -- the communication requirements are more demanding than could be accomodated by the STO wire.