Going back...
So, the problem(s) started after the injector install...?
Can you remember anything that may have been "suspect" during the install...?
(kinked/broken/pinched/stretched/swapped wire...?)
Did you disconnect battery anytime you removed/replaced a module connector...?
If you can connect the battery back on, and use DMM to measure voltage from battery POS+ terminal (wrt NEG-) all the way to the positive side of each load/device (should be very close to battery voltage... the drop should be less than 0.2 or 0.3V).
Then repeat the process measuring voltage from NEG- terminal (wrt POS+) all the way back to the negative side of each load/device (checks grounds).
If you see a large drop without cross a load/device, then you have found the problem.
Last edited by joecar; September 23rd, 2008 at 05:18 PM.
i by passed all modules on the star and still could not connect.
i get less than 1 volt at the DLC (OBDII) that seems to be in range from what i`ve read.
i think it is odd that i read 12volts at the lower fuse box and it is audible to ground.
i don`t know if that is normal.
i don`t have a drain. (DMM between neg- cable and neg- battery)
no voltage drop away from the battery.
after the injector swap there were a couple instances of this but now it
seems to be permanent, this makes me think there is something broken.
all light, gauges, stereo work perfectly now with a new battery.
other than the fuse box "oddity" (if it is)
can battery cables wear out without signs of obvious wear?
i can`t get the car into the shop until next week so i have a few more days to
poke and prod.
Cables can sometimes corrode under the insulation in the following instances:
- someone pierced the insulation to take a measurement, and then they neglected to seal the tiny hole (with paint), or they sealed it with silicone rtv (which produces ammonia over time, which corrodes the copper wire);
- moisture entered via the crimped on terminal and seeped up the copper wire stands.
I don't like the continuity test because many loads in parallel "appear" to look like continuity to ground...
I like the voltage drop test better.
If you have a short, did any fuse pop...?
well i got it to download/upload today.
also did a VATS relink,
LMAO i forgot how slow the stock PCM is to flash/read.
once that was done i attempted to start the car to no avail.
it just cranked and the fuel pump did what its been doing.
only "U" codes again no P1626, and after i checked the DTCs
it would not connect again and, the security light was flashing.
another strange thing, the doors would lock with the key in the ignition
even though i have option turned off.
and when locking the doors with the remote,
it would give the ring like when you try to lock the doors with the key in the ignition and not lock.
on the second try they locked.
i`m not sure what i did to get it up, other than reconnect the battery,
and why it would not start.....
Ok, so with only PCM and tunetool on bus, you can talk to PCM... or did you "bench-harness"...?
Questions:
- do injectors fire (put finger on each one while cranking (long arms...?)...?
- do spark plugs fire...?
Fuel pump is cycling...?
Swap fuel pump relay with a different similar one and see if same thing happens.
Check fuel pump relay socket/wiring for bad connections.
With a fused(!!!) jumper wire, does fuel pump run...?
Your PCM may be bad... and also your BCM.
There is a way to obtain BCM DTC's... it involves removing a fuse from the LHS dash fuse panel (I have to look up which one) and cycling the ign key, and the Security light flashes a code sequence... I'll post up when I find it.
U codes mean that one or more of the modules (EBCM/ABS, SIR/airbag, IPC) can't communicate with the PCM or vice-versa.
this was through the car, for some reason it decided to "hook up"Originally Posted by joecar
i uploaded and downloaded to the PCM.
you proved the BCM does not interfere with that.
it could still be the cause of P1626
remember i am using 2 PCMs
i am definitely interested in this.
i bypassed the IPC, EBCM and the SDM at the star and still could not
flash/read.
even after i flashed the PCM this time the car ran like poo.
there is something up with/on the class 2 comm.
Last edited by mr.prick; September 25th, 2008 at 12:31 PM.
Viewing BCM diagnostic trouble codes...
On-Board Diagnostic Features
Retrieving and Displaying DTCs
If a malfunction occurs in a system monitored by the BCM, the BCM stores a diagnostic trouble code (DTC) in memory. A current DTC means that the fault is present when the diagnostic mode was entered. Current DTCs are displayed with a beginning number 2 (2X). A history DTC means that the fault occurred sometime after the DTCs were last cleared from the BCM memory. History DTCs are displayed with a beginning number 3 (3X).
The DTCs are displayed as flash codes through the security indicator lamp on the instrument cluster when the BCM is in diagnostic mode. Perform the following steps in order to enter the BCM diagnostic mode:
1. Turn the ignition switch to the RUN position.
2. Turn the ignition switch to the OFF position.
3. Remove the Radio fuse from the I/P fuse block.
4. Turn the ignition switch to the ACCY position.
5. The BCM sounds 1 or 2 audible warning tones.
6. Within five seconds, turn the ignition switch to the OFF position and immediately (within 1 second) back to the ACCY position.
7. The BCM sounds 3 audible warning tones.
The BCM will begin flashing trouble codes using the security indicator 4 seconds after entering the diagnostic mode. Each series of quick flashes followed by a pause of the security indicator lamp on the instrument cluster represents a number in a 2 digit DTC. Each 2 digit DTC is displayed three times before the next DTC is displayed. DTCs are displayed in numerical order. Once the last DTC is displayed, the list begins again with the first DTC. This display rotation continues until the diagnostic mode is exited.
DTC Display Order
In the diagnostic mode, diagnostic trouble codes (DTCs) are displayed in the following order:
1. DTC 12
2. This indicates that the BCM is in diagnostic mode. Any current DTCs (21 to 25) then any history DTCs (31 to 35)
3. These are displayed in numerical order. The remote control door lock transmitter diagnostic DTCs (41 to 45)
4. These DTCs will display if the keyless entry transmitter buttons are pressed while in the diagnostic mode. The begin configuration display (DTC 55)
5. DTC 55 and 2 single digit configuration numbers are always displayed. The first digit following DTC 55 is the hardware configuration. The second digit is the software configuration. After the configuration numbers are displayed, the entire list is repeated beginning with DTC 12.
If only DTC 12, DTC 55 and the configuration digits are displayed when the BCM is in the diagnostic mode, the BCM has no circuit failure DTCs set and is operating properly.
If DTCs are not displayed, or if the BCM cannot enter the diagnostic mode, refer to Cannot Enter BCM Diagnostics.
If any other DTCs are displayed, refer to Diagnostic System Check - Body Control System.
Input and Output Tests
Lock Test
While in diagnostic mode, if either door lock switch is pressed, the BCM will flash the fasten seat belt indicator on the instrument cluster and sound an audible warning tone. The BCM will also attempt to perform the operation normally performed by the switch operation. In this case, as long as the system is functioning properly, the BCM will lock the doors. This is a way to test the door lock actuators, switches and associated wiring without removing the door trim or components.
Tamper Sensors Test
The BCM will also respond to a change at either shock sensor input. The tamper input is activated by minor blows to the vehicle. The shock input is activated by heavy blows. In the diagnostic mode either the tamper input or the shock input will cause the BCM to activate the horn relay, and the horns will sound. The BCM will also flash the fasten seat belt indicator on the instrument cluster and sound an audible warning tone. An effective method of checking the shock sensor and associated wiring is to tap on the shock sensor while in the diagnostic mode.
Theft Deterrent Outputs Test
Switching the interior lamps switch on and off while in the diagnostic mode will cause the BCM to flash the fasten seat belt indicator on the instrument cluster, sound an audible warning tone, and flash the courtesy lamps. On vehicles equipped with theft deterrent, each transition of the interior lamps command input will cause the BCM to proceed to the next action in the following list:
1. The courtesy lamps flash
2. The horns sound
3. The exterior lights flash
Clearing BCM DTCs
Current DTCs (21 to 25) are displayed in the diagnostic mode as long as the BCM detects the fault. Once the fault is corrected, the current DTCs are cleared by the BCM.
To clear history DTCs (31 to 35) press and hold the door unlock switch for four seconds while the BCM is in the diagnostic mode. The BCM will sound three audible warning tones to confirm that the DTCs are cleared.
To clear BCM history DTCs (31 to 35) on vehicles without power door locks, back probe the position for the door unlock signal input with a fused jumper to ground for four seconds. The BCM will sound three audible warning tones to confirm that the history DTCs have been cleared.
Leaving Diagnostic Mode
Perform the following to leave diagnostic mode:
1. Turn the ignition switch to OFF.
2. Reinstall the Radio fuse in the IP fuse panel.
3. Turn the ignition to RUN.
Here the rest of the BCM stuff... the GM SI has it scattered around... I wonder what they were [not] thinking... it almost seems like an after-thought...
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