blkchevyz

wouldnt it be throwing a code if it was a sensor or something in the transmission?

did you try the old tap the starter with a wrench lol

spy2520

iTrader: (3)

I did try tapping it, but bridging the gap with a screwdriver spins the starter, so it appears the starter does work properly. And I tried hooking up my flashscan but it keeps saying "no vehicle", the obd port does have power though. I also measured voltage at the s wire while someone turned the key, nothing.

Ill_Born_ss

just to verify, you have good battery voltage! Does any other scanner type tool see the computers?

I had done an edit to the earlier post, but then I seen this. Mainly I thought you had/have a problem with the range selector(PRND321) Park/Neutral switch... but if you have no computer, ECM/TCM!

spy2520

iTrader: (3)

The car ran fine before the trans, I remember having problems scanning this car before. How could I diagnose if the TCM or ECM went bad?
I've tried jump starting the car also but I'm getting 12 volts from the battery.

Ill_Born_ss

Check for actual battery voltage a fully charged battery has 12.6 volts and at 12.3 volts it has lost 50% of its capacity. For the TCM/ECM you would start with the fuses and whether or not there is power there. Also check the ODB port wiring/pins, if you look back at post 19 my edit will give you some pins to check for power and ground.

Just a note I did encounter something like this before and it turned out that the fuse box main connecters (the big ones installed and removed by the bolts inside the box) were not properly installed as in when loosening them off the bolt raises, don't allow this to happen you must keep pressure down to cause the thread to push the connector out of its socket. The same for reinstalling them you put the connector into the guides for the case and then pull the connector into the box with the bolt (not pushing in by hand) If you do venture into this be sure to disconnect the neg battery cable and do not allow it to touch the neg terminal until you are finished. P>S> coat ALL the connector pins liberally with die-electric grease before reassembly and after push all the fuses in to seat them.

spy2520

iTrader: (3)

I will certainly check that.

I did some searching on all-data (aka some-data) and "scanner powers up but won't communicate with vehicle" is definitely an indicator that the modules are not all talking to each other and this is something that will not allow the car to start. It specifically states that the vehicle will not start if the modules aren't communicating with each other (and the scanner).

I am in the midst of a blizzard though so this is going to have to wait. I printed out a bunch of **** though so hopefully i can diagnose and get to the cause quickly.

spy2520

iTrader: (3)

Looks like if its not a fuse, I'm looking for a short to ground or power somewhere. According to my diagnostic chart there is only one instance where an open on a ground circuit will cause this condition.

Ill_Born_ss

As I mentioned for your specific conditions there was the fuse box stuff, but if it is indeed the range selector/ park/ neutral I have found that the harness coming around the bell housing there is a spot where the harness actually rubs on one of the bell housing bolts and has actually broken wires inside right there.

spy2520

iTrader: (3)

I'll check that out as well.

Ill_Born_ss

spy2520, I was out and about when something came to mind. I have 2 questions/ comments.
1- you are using a master key, not a valet key (going to assume you are)
2- there is one little known thing that can do this to you... don`t kick yourself or anyone else if this is it. Turn off all power accessories, close all the windows, remove the key, set the park brake and get out. Close the doors and hood and trunk and stand back 10' or so! Now take your remote transmitter in your hand and press the lock button twice. Wait 1 minute and then press the unlock and proceed to get in and start your car. Let me know!

spy2520

iTrader: (3)

damn, i'll try that. I believe this is the main key, although i have no clue, this was the key i was given, i'll have to ask.

spy2520

iTrader: (3)

I noticed that the lever on the EBCM is broken, could it be that its not getting a good connection and causing the car not to start? Everywhere i read says the car should start even with it unplugged.

Ill_Born_ss

actually it could if there is any damaged pins or a bad connection and no it would not start most likely as these BCM` are different than their predecessors. The thing with the keyfob was exactly for that type of thing, every once in a while one of these cars when reconnecting the battery and certain things are met and the terminal briefly does a touch/disconnect/touch the security system VTD(vehicle theft deterrent) and the CTD(content theft deterrent) systems fail as in one unit sets itself and the other does not. The only way to reset them is as I mentioned earlier. But only 1 of these systems can turn off the ECM when it sets (VTD) and from what I remember they both go thru the BCM. For this I will have to refresh myself and get back to you, meanwhile disconnect the neg battery and remove that connector and verify the pins male& female are ok and try to reinstall it properly. Also did you check all the fuses in the IP fuse box?

spy2520

iTrader: (3)

I've checked all the fuses under the hood and also the ones on near the passenger side floorboard. So far nothing blown.

Ill_Born_ss

Any chance this car and its previous owner had a breathalyzer lock installed on it? Remove the panels around the ignition switch and check for any loose or repaired (yellow)( some models D-GN & D-GN/BK) wires I believe, while your there verify all the connectors are properly seated on the ignition/ key transponder assembly.

spy2520

iTrader: (3)

I can check when i get home, but the car definitely drove into my garage fine before the transmission swap. Had issues where the filter kept dropping down, pump sucking in air/ no movement. Changing the filter and seal fixed the problem temporarily but we knew the damage had been done.

I've been dealing with this car for a few years and the only problems i ever saw it have was transmission related, thats why this electrical **** is baffling me at the moment.

Ill_Born_ss

Thanks for the extra info, the only things that can do this are the VTD, the ignition switch/transponder,(with these two they shut off the fuel and the computer ECM) the P,N safety and or the PRND321 range switch (this just prevents the start relay from engaging, you will hear the fuel pump cycle each time you turn the key) All your other electrical seems to function as it is supposed to except for the range indicator in the DIC. 1 other thing may prevent the system to return to a ready state is a faulty RAP relay, whether it is stuck or blown. Not the radio RAP relay which if you are in your car with the doors closed and radio on and then turn the car off, the radio stays on until you open the drivers door or 10-15 minutes go by for it to shut down/reset itself.
I will see if I can post the test for the RAP after lunch here.

Ill_Born_ss

2007 Chevrolet Impala 5.3L Eng SS







Fig 6: S/ROOF, DR/LCK, RAP Fuses & RAP Relay, DOOR UNLOCK PCB Relay - Driver, DOOR UNLOCK PCB Relay, & DOOR LOCK PCB Relay Power Distribution Schematics
GM1759834
Courtesy of GENERAL MOTORS CORP.

best bet is just test swap the relay with another known good unit

spy2520

iTrader: (3)

I swapped what i believe is the rap relay and no change. The panel is poorly labeled so i'm gonna double check in a manual to make sure i got the right one.

Your description of the condition is accurate, fuel pump cycles, everything seems fine, no shift indicator. The shifter does move through all the positions fine, and i double checked the position of the manual lever and it appears it is in park when the shifter is in park.

If it were the ignition switch shouldn't i still be able to scan for codes? Not that it would help, but i would still have the ability i assume.

Ill_Born_ss

Ok, before I dig out some serious diagrams... can you check
- with key on and right hand on the passenger side of the console and listening, can you feel/hear the shiftlock solenoid as you apply the brakes.
- can you try to start the car in every shift detent position.

As for the ignition switch/transponder reader it can cause the computer ECM to shut down using the VTD system.