shoemike

iTrader: (25)

i cannot connect to the PCM through the OBDII port.
i can retrieve DTC`s and log but cannot upload or download.
the car starts and runs poorly.

the battery is new,
i have checked all the wires at the serial bus (STAR) directly to
each module except for the IPC gray wire (where does it go?)
both grounds at the OBDII port for continuity
and, the BCM key feed/return measure
exactly the same as my key.
lights, stereo and windows work and, i tested all fuses.
the problem is not the PCM (i`ve used 2) or the BCM
VATS inactive and the voltage at the BCM is what it should be.

where do i check BLUE pin 2/RED pin 39 and OBDII pin 16 (12volt sources) to,
the main fuse box bolt?

aside from replacing all relays and
checking the IPC to serial bus L (gray wire)
what wires should i check?

sreve

iTrader: (3)

have you checked the com port? i have had this problem when my logger
wants to use the same com port as win flash.

shoemike

iTrader: (25)

do you mean the OBDII or my PC?
to be clear, the problem is with the car

i checked the serial port (star bus) for "continuity" and all but
the IPC (i don`t know where to plug into)are good.
i checked the OBDII port and all is good. (Both grounds and signal to PCM)

i really want to check the IPC, so i can completely rule out the serial port. (star bus)
i also would like to know where the best place to plug into from the
PCM RED connector pin 39 and BlUE connector pin 2. (12 Volt References)

wait4me

iTrader: (10)

If you can read codes and scan the logs / pids, then i would say you have some other kind of issue? what software are you using? If you are talking to the pcm, then it should read/write as long as you dont have something messing with the comms like an add on radio ect.....

For the obd2 connecter you just need 1 12v to batt, 2 grounds and 1 pin to pin58 on the pcm for serial output.

shoemike

iTrader: (25)

i think it is odd that i can scan PIDs and DTCs and not up/download.
the fact that i cannot connect "completely" and the car does not run
is not coincidence.

i am using EFILive. (of course)
the problem is not with EFILive and i`ve tried 2 PCMs .
so all i can think of is an open/short circuit or maybe
a module failure.
can a module failure can cause this? (other than PCM)

i have not been able to find the location of the only
wire on the serial connector that i have not tested (IPC) pin E.
i would like to rule that out.

i found this person had almost the same problem.
https://ls1tech.com/forums/showthrea...43#post9032643
but his car would run and, my gauges work.

i use a power inverter through the cig lighter.
possibly this has blown a fusible link.

at this point any suggestions are welcome.

shoemike

iTrader: (25)

can a bad BCM cause a lock out of the PCM?

eallanboggs

iTrader: (1)

Do you have any "U" series DTCs?

shoemike

iTrader: (25)

yes
and P1626 consistently.
i can get the car to start and idle after unplugging/replugging BCM.

do you know if unplugging the BCM would prevent the PCM from being uploaded/downloaded?

i can scan/log PIDs but, i cannot uploaded/downloaded a
tune file from/to the PCM.

i know the BCM is not on the class 2 serial com. port but,
can it interfere with the class 2 serial com.?

i know i don`t have the "classic" BCM symptoms but
i have probed all wires to each module and hot/ground wires for
continuity and every one i checked is good.

i have tried 2 PCMs and got the same outcome as well.