Guys,

This might be totally psychological so I am after some 2nd opinions here.

I recently reporgrammed my PSOM to reflect the larger tyres that the previous owner had fitted bacause I found out my speedo was reading about 10mph low at 60mph (i.e. the vehicle was doing 70!) which is a bit of a risk with all the speed cameras about these parts...

Anyhow I digress. Since fixing the PSOM I noticed that the truck runs much better and doesn't seem to bog down in 3rd on the hills etc. I note there are wires running from the PSOM to the ECU etc. so was wondering if the system is compensating (correctly) for the different rolling radius of the tyres and altering the mixture etc for better performance.

As I said, might be imagining things...

Simon.

 

'Correctly' is a little too ambiguous. If the re-programming you have done was correctly done in order then yes. The re-programming of the PSOM/ECU is compensating for the changes.

reference: http://www.off-road.com/ford/bigbroncos/tech/psom.html

 

By reprograming PSOM(programable speedo) you will change the shift points of your e4od tranny- poss giving more performance out off your Bronco-I put a electronic speedo correction device on my 95 and played with it changing the dipp switches and could get it to shift and take off like it was in 4x4 low- very fast for a short distance(didn' leave it that way though)

 

The suggestion that iot changes the shift point tallys with what I am experiencing. I did it in accordance to the document on the link given by tHeCoS (expect the wire colors are different). Was well worth the sore thumb from having to press the buttons on the speedo so many times.

 

I recently tried going through this same procedure on my '92 Bronco, after installing a set of 32's. I got as for as retreiving the current information "967 CAL", before I had trouble locating the "Dealer mode programming enable single-terminal connector", and thus forth, "Circuit 567(LB/Y)".
Can you better describe exactly where this connector/wire is located, or do I have to have a Manual for this prcedure?

 

Same issue for me. If you follow the link in in the conversation above it states the color of the wire for ALL trucks is (YB/L) however this is wrong because mine was something like orange and brown.

To locate:
Sit in driver seat and lean over to passengers side so head is on passengers seat. Look at bottom centre of the glovebox. The wire is fitted to a hole in the moulding just behind the bottom edge of the glove box. Mine had a grey shroud on it but it will be one wire on its own clipped to that lower edge. Its drops about 3-4" when its released from the carrier.

once located look lower and there is a metal bracket that holds the heater or dashboard assembly - this makes a suitable earth to short the above wire to.

If you need pictures let me know and I'll take the digicamera out to the truck.

 

Great detailed description!!!
I just went out into the parking lot with a binder-clip and a paper-clip and reprogramed the PSOM. After turning the key to off, and then on-checking it again, it looks like the new constant has been stored.

Thanks again - and please check out my next (and yet another) post on my 4x4/ transfer-case not engaging.

 

No worries, glad it worked because when I asked the question before no one could help me so I had to work it all out the long way and I wouldn't fancy anyone trying to repeat it again.

Why not add to my reputation if you were happy with the answer? Click on the little "scales" top right hand corner of the messages... *grin*

Simon