lets get technical.
#1
lets get technical.
ok i got a 2.3 weel of course this is the place for this.
symptoms:
no command from pcm to activate fuel pump after initial time out, fuel can be over ridden by jumping the DLC to ground. and truck seems to run fine.
no communication with pcm via scanner.
not shure what else is inop.
trouble shooting done.
inspected all grounds to pcm pin 20, 40, and 60 good
verified voltage on pins 1, 37, and 57
ohmed wires for grounds with DVM within spec
removed and tested DIS module
verified ign gnd on PCM pin 16 , DIS pin 7 and CKP pin 3
got pulse on DIS pins 2 and PCM pin 5
also got pulse on DIS pin12, and pin 4 PCM
no bad fuses.
at a loss here. i believe it is a PCM problem
DAMN newbs
symptoms:
no command from pcm to activate fuel pump after initial time out, fuel can be over ridden by jumping the DLC to ground. and truck seems to run fine.
no communication with pcm via scanner.
not shure what else is inop.
trouble shooting done.
inspected all grounds to pcm pin 20, 40, and 60 good
verified voltage on pins 1, 37, and 57
ohmed wires for grounds with DVM within spec
removed and tested DIS module
verified ign gnd on PCM pin 16 , DIS pin 7 and CKP pin 3
got pulse on DIS pins 2 and PCM pin 5
also got pulse on DIS pin12, and pin 4 PCM
no bad fuses.
at a loss here. i believe it is a PCM problem
DAMN newbs
#3
Fill in some info about your truck.
In general, the fuel pump comes on for 2 seconds when the key is turned to Run.
It primes the system to full pressure.
After you crank the starter and the engine starts, the fuel pump relay ground is (still)controlled by the PCM (Pin 22 on a 1993) but now it is as a result of seeing the Crankshaft rotation (PIP or CID?, I know not which) signal.
The Data Link connector has that same wire present (LB/O), so grounding it keeps the fuel pump relay engaged even if the PCM is failing to provide you that ground.
You could have a bad ground in your inner front fenders, radiator support or near the battery- (a small wire). You could have a bad crank sensor, but I would think it would affect ignition and injector timing if that were the case.
More specifically, ensure that PCM Pins 40 and 60 have good continuity to ground #101 (radiator support by the battery) and that Pins 20, 6 and 3 have good continuity to Ground 200 (driver side upper inner fender, closest to the hood hinge).
No connection to PCM with a scanner could be a blown fuse (a lot of Fords share that power with the cig lighter).
In general, the fuel pump comes on for 2 seconds when the key is turned to Run.
It primes the system to full pressure.
After you crank the starter and the engine starts, the fuel pump relay ground is (still)controlled by the PCM (Pin 22 on a 1993) but now it is as a result of seeing the Crankshaft rotation (PIP or CID?, I know not which) signal.
The Data Link connector has that same wire present (LB/O), so grounding it keeps the fuel pump relay engaged even if the PCM is failing to provide you that ground.
You could have a bad ground in your inner front fenders, radiator support or near the battery- (a small wire). You could have a bad crank sensor, but I would think it would affect ignition and injector timing if that were the case.
More specifically, ensure that PCM Pins 40 and 60 have good continuity to ground #101 (radiator support by the battery) and that Pins 20, 6 and 3 have good continuity to Ground 200 (driver side upper inner fender, closest to the hood hinge).
No connection to PCM with a scanner could be a blown fuse (a lot of Fords share that power with the cig lighter).
#4
looked @ all grounds.
i didnt find any bad fuses. nor did i verify the cig lighter operates.
i also do not believe that the cmp has failed due to the fact that the ignition nor injectors are affected.
i will call the customer and verify cig light operates.
thanks for the info i was begining to feel like this was a "JEEP" website and these questions was over everyones heads.
no offense to anyone.
i didnt find any bad fuses. nor did i verify the cig lighter operates.
i also do not believe that the cmp has failed due to the fact that the ignition nor injectors are affected.
i will call the customer and verify cig light operates.
thanks for the info i was begining to feel like this was a "JEEP" website and these questions was over everyones heads.
no offense to anyone.
#7
yes - you are over everyone's head here... but I tune ECU's professionally. I would agree with the PCM being bad theory - to bad you can't communicate, knowing DTCs would make this much easier.
What else would you expect on a forum where most of the users swear in a benifit from a cold air intake? (wink wink)
What else would you expect on a forum where most of the users swear in a benifit from a cold air intake? (wink wink)
#8
I forgot to add:
Was an electronic component recently replaced? Like a sensor? On that Taurus we were working on, the owners DPFE sensor went bad and they put one on it from a previous body style. As soon as we got the new PCM installed the computer was showing a wrong voltage on the DPFE.
I'm pretty much sure thats what messed up the previous PCM.
So before you install a new PCM make sure that all the sensors are correct or you maybe doing this again.
Was an electronic component recently replaced? Like a sensor? On that Taurus we were working on, the owners DPFE sensor went bad and they put one on it from a previous body style. As soon as we got the new PCM installed the computer was showing a wrong voltage on the DPFE.
I'm pretty much sure thats what messed up the previous PCM.
So before you install a new PCM make sure that all the sensors are correct or you maybe doing this again.
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