No start.

[jarek m]

So the truck lasted problem free about two years after big rebuild, good run for a 200k truck with $2k refresh.

Air ride compressor is out again after 50k miles or so.
http://i32.photobucket.com/albums/d45/Basia678/E43D2AC1-E884-4FEE-915F-AE1655CE4D24-1795-000001943E5E02F5.jpg

But the big problem is new no start and dead OBD2.
http://i32.photobucket.com/albums/d45/Basia678/73394DFD-3D83-4247-9A65-30C855F6FE90-1777-000001924974D981.jpg

The truck just died on the go and wouldn't crank after. It has all the symptoms of a dead battery but its not it, I also bench tested the starter... Ok.
Recently I started getting low engine power and it would clear by turning the ignition off.
All fuses ok, starter relay tested ok.

[HUMTECH]

Do you have a remote starter that is tapped into your data line right behing the data link connector? If so remove the splice and try that.

[jarek m]

Not anymore, that's the first thing I took out, reconnected al the splices

[jarek m]

Also today I astablished that starter cranks the engine when jumped, no start. Ignition relay clicks but starter relay don't, even when swapped.

[HUMTECH]

Try using a jumper wire across pins 87 and 30 of the starter relay and see if starter cranks

[HUMTECH]

http://gsi.xw.gm.com/image_en_us/gif/000/001/566/1566882.gif

[Hellz]

is teh passlock icon lite on your dash?

[jarek m]

is teh passlock icon lite on your dash?

It comes on and off once a week

[jarek m]

Try using a jumper wire across pins 87 and 30 of the starter relay and see if starter cranks




The truck started crankin but no start.

[jarek m]

10A crank fuse lights up when key in crank position...

Starter relay 87, 30 good 85 goes positive when key in second position, so I'm assuming that 86 should get grounded for cranking?

[HUMTECH]

Check the other 2 pins of the start relay, one should have power in run position and the other should have ground in the crank position

[HUMTECH]

If its not getting a ground during crank ecm is not sending crank signal.

[jarek m]

If its not getting a ground during crank ecm is not sending crank signal.

Thats what it looks like. You wouldn't happen to have a decent ignition diagram?

[jarek m]

No crank signal, no OBD conection and no spark or injection... ECU

[HUMTECH]

As long as the data line is good, power and ground at ecm is good then ecm is bad.

[jarek m]

That's where I'm heading, good to have second opinion, thanks.

[jarek m]

All grounds tested ok and 2 pink tested 12v on the ECM plugs.

http://i32.photobucket.com/albums/d45/Basia678/6FEFE4AB-6EB6-4F32-BDAB-4BEA15857F43-1676-000001850E9D27FD.jpg

ECM looked ok in every way
http://i32.photobucket.com/albums/d45/Basia678/4B65F5E4-FD3E-4D93-83AE-8C47F719F58C-1676-000001851BC7E15F.jpg

http://i32.photobucket.com/albums/d45/Basia678/BF52950E-94EF-4DC7-A89D-BA513908DAA6-1676-0000018516DEC33A.jpg

[jarek m]

New ECM in route...

[jarek m]

New ECM still no start :/

[HUMTECH]

Did the dealer program it for you

[jarek m]

No, eBay seller, "ECM programers" had a feedback of 100% couple thousand sales.

[HUMTECH]

so did they preprogram it for you with your vin#? If not you need it programmed. If they did you still need to do a theft learn follow this procedure.
1. Turn ON the ignition, with the engine OFF.
2. Attempt to start the engine, then release the key to ON, vehicle will not start.
3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
4. Turn OFF the ignition, and wait 5 seconds.
5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes, the vehicle is now ready to relearn the Passlock? Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.
Important: The vehicle learns the Passlock? Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
6. Start the engine. The vehicle has now learned the Passlock? Sensor Data Code and/or password.
7. With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.

[jarek m]

Tried this procedure two times, no change.

[jarek m]

Passlock light doesn't go off after 10 min during the procedure, waited to 15m and it still wouldn't go off so second time i did this.

insert key and try to start the vehicle. do not turn the key off, let it sit in the "ON" position for 12 minutes

turn key OFF and remove key, wait 5 to 10 secs, and put key back in and just turn to the ON position ( dont try to start)

do this a total of 3 times.
start- on wait 12 mins- off remove key- on wait 12 mins- off remove key- on wait 12 mins- off remove key and start H2 up normally.

[HUMTECH]

Try original procedure but dont try to start at any time, just turn on and wait for light to quit flashing, im assuming its flashing? do that 3 times and see what happens

[HUMTECH]

You never said if they programmed to your vin#? Needs to be done before theft learn

[jarek m]

Yes, It's been programed to my vin#.

PassLock light comes on exactly 1 minute after turning the key and stays constant on (not flashing) for 15min+ after whitch I switched rutines because the light wouldn't go off and the other routine doesn't call for the light to go off.

[HUMTECH]

Well im stumped. Wish I was there with my tech 2 would be much easier to get to the bottom of it. Ill look for more info for ya

[jarek m]

Thank you, you helped regardless.

[jarek m]

Ok an update, I decided to start over and found PCMB fuse is blown now. Replaced it and the truck cranks now, but no start. OBD2 communicates, no codes. PCM1 fuse gets 0v in all key positions, there is no fuel pressure and fuel gauge is not working...

[jarek m]

I'll try the passlock procedure again. Fingers crossed!!!

[jarek m]

Well passlock procedure didn't work. But i got it running.. Kind off.
I jumped PCM1 fuse to the battery and it started! And stayed running till i puled the jump.

[jarek m]

http://i32.photobucket.com/albums/d45/Basia678/6548D3F8-F1D1-4110-AC35-04959BC5AE5F-368-0000005055D1F899.jpg

http://i32.photobucket.com/albums/d45/Basia678/B4F4FFAC-C12F-4B48-8F70-F5D4510EAFFC-368-00000050596FD8FF.jpg

http://i32.photobucket.com/albums/d45/Basia678/B9506B28-5251-4BDC-93F5-6FD0C509828D-368-000000505E60083C.jpg

http://i32.photobucket.com/albums/d45/Basia678/63C572B4-8A56-40DE-B273-C1413B24F19D-368-0000005052F566C3.jpg

[jarek m]

Technically.... If i jump the Pcm1 fuse to the ignition relay that should work...

[HUMTECH]

Is that jumper wire in the picture for the drl lights mod to come on with headlights? I ask cause any blue wires from underhood fuse block are lighting circuits. Could have caused damage to bus bar in fuse block. If you jump the pcm 1 circuit it should work but could put too much draw on that circuit causing more damage

[jarek m]

Is that jumper wire in the picture for the drl lights mod to come on with headlights? I ask cause any blue wires from underhood fuse block are lighting circuits. Could have caused damage to bus bar in fuse block. If you jump the pcm 1 circuit it should work but could put too much draw on that circuit causing more damage

Yes i did this last week while the truck was down

[jarek m]

Come to think of it the truck was going trough it's usual clicks and noises routine before cranking after the breakdown till I did that drl mode.... I only noticed it missing after i jumped pcm1 end heard that sweet music again ushering life in to the engine,lol

[jarek m]

:twak: Did I fry the fuse box?

[HUMTECH]

Might have caused an open circuit to the pcm 1 fuse. When i have time tomorrow ill get the connector end views so you can test it

[jarek m]

Thanks a bunch!

[HUMTECH]

This is the black connector under the fuse block. Check from pin location c2 to where the pcm 1 fuse is located. Should have continuity from one side of the fuse location to this pin location.
http://gsi.xw.gm.com/image_en_us/gif/000/000/362/362761.gif

[HUMTECH]

Also check your ign e fuse

[jarek m]

Will do, thanks.

[HUMTECH]

Oops, pin location a12 sorry, c2 is the connector number

[jarek m]

No circuit. :(.

Local hummer HQ wants $580... Going to call it in tomorrow.

[HUMTECH]

You checked A12 to pcm 1 fuse right? Making sure you got my last message

[jarek m]

Yes.

[HUMTECH]

Well sounds like your fuse block is buggered from where i stand

[jarek m]

DL got one in, no time to go pick it up...

[jarek m]

Ooooooo...:clapping:

http://i32.photobucket.com/albums/d45/Basia678/5CDE48B8-C916-4509-962D-06A2B03D1082-699-000000882A2D9B99.jpg

[Hellz]

this whole thread has me cringing at the thought of any electrical work on my H2.

[HUMTECH]

Get it running yet

[jarek m]

Yes, installed the new box and it fired up no problem! What a trip!

[HUMTECH]

Good to hear