rodgebone

put the pcm in another car and was able to pull code 102 for the mafless tune so must be in the wiring itself. we have confirmed its definitely not the pcm. more checks and tests to come in the next few days once we have the car back from the dyno shop

rodgebone

update: we have confirmed we can pull codes with the pcm in the Jeep using HP Tuners but still no check engine light coming on when inducing codes. will play with it more in the next few days. at least some form of progress here!

rodgebone

after success using HP Tuners to induce and pull codes we still cant get the MIL to come on when when a problem arises nor can i get my laptop palmer software to pull codes even tho it will log performance. i must be missing a circuit in my custom wiring job in the Jeep itself as we know the pcm is working perfectly and can pull codes and set off the MIL when installed in another car. i tried applying 12V battery power directly to the orange wire on the pcm @ pin 19 on J1 blue (which is supposed to be the only ignition feed) only to find i lost all spark so couldnt even start the car - i dont understand this as 12v is 12v whether it comes from the battery direct or via the ignition switch. as well it still wouldnt produce codes. i reckon i am missing the signal for "diag enable" between the PIM and the DLC as well as a couple of other circuits from the PIM and BCM to the DLC (as mentioned before). at least we can put it on HP Tuners occasionally to check things but I am giving up trying to make the MIL work to alert the driver. if anyone ever comes up with an idea please let me know. it would be nice to have a functional MIL.

Doubledip

ok... i havent had a car in to test but a mate has got it working on his boss's car.....

it works in reverse... dont know why but this is what he has told me...


with no codes in the PCM - PCM supplies an earth on pin 46
code set in PCM - PCM drops earth on Pin 46

so would need to use a changeover relay