NJJOE4X4

Ok,.. put new crank position sensor in, broke 2 exhaust bolts on both sides so looks like I have another project on top off no spark. I put PJ blaster on the bolts too. Gonna drill the bolt and try to extract it. Those bolts are not that strong or the heat from the exhaust makes them soft over time.

With the new crank position sensor still no spark same thing.

Joe

3boystoys

Still getting this?
U1016 H C " Loss of Communication with PCM "

How are you testing for injector(s) firing and for spark?

NJJOE4X4

no current codes just history codes. right now I`m gonna fix the bolts that broke and then I`ll start looking for the no spark problem again.

testing the no spark, pulled plug wire from spark plug put new spark plug to plug wire then ground it to the engine block "wife crank the engine "no spark on both sides of the coils.

I think I`m gonna have to find a good scanner tool.

Joe

Bill Curlee

Lets just for the hell of it,,, try something. To the left of the BCM, there are two thin connectors. Find the one with FOUR wires. Pop the TOP off of that connector. You should have a shorting strip that removes with the cap.

With that cap removed, see if you now have spark. Report results. If that doesnt help, reinstall the cap and we will have to keep looking.

You should have comms with ALL the modules. Especially the BCM and PCM!

3boystoys

Something's weird here, a no start condition and ZERO codes from the DIC. Should would be interesting to see if there really are crank pulses.

NJJOE4X4

Bill I removed the thin cap on the 4 wire connector, tried cranking it wife not home for me to check for spark, no start or misfire , tried with the other thin strip removed the cap and cranked same result, nothing.
I did get a code to pop up BO507.
LH DRL relay Ciccuit.

If I get a tech II will that show me what the problem is?

3boystoys

A tech II will show you all the signals needed to start/run, it's up to you to interpret them. Do you know if the injectors are opening/closing? You can listen to them during cranking with a long screwdriver or get a NOID light and disconnect 1 injector, put the light on the connector and see if it lights up during cranking. First think I'd do with a scanner that could, is actually check for crank/cam pulses.

helga203

I've had this code since early 2000 (U1016 H C " Loss of Communication with PCM). Car starts fine. Just some info. Man how frustrating. I hope something pop's it's ugly head out.

BigGun

You still have this code and the car starts and runs?? I did not think it was possible for the car to even start if you had no communication with the pcm. Please explain.

Bill Curlee

Start checking voltages on all the FUSES that are powered by the IGNITION SWITCH. Just a stinking feeling that you are low or missing a critical Hot In Run and Start ignition powered supply voltage/

This is a 99 switch and the loads it supplies:

martysauto

It depends what module loses com with PCM. Door, seat, hvac or abs com loss will not cause a no start. Bcm is a different story.

Bill Curlee

Marty is 100% on the mark. You can remove ALL the modules from the C5 other than the BCM and The PCM. If you remove BOTH STAR connector buss bars and jumper the BCM & PCM serial lines together, the car will start and run normally.

That being said,,,,, IF,,,,, the serial data buss is corrupted and or shroted, the car will NOT work properly.

Bill

4DRUSH

Broken connector on head ground wire?

happened to me once

NJJOE4X4

I`ll start checking the fuses tomorrow. and recheck all the grounds.
That G107 ground that I can`t see or feel behind the drivers side head.
anyone know where it is or a pic would help.
http://www.ls2.com/boggs/corvettegro.../G105_G107.jpg

Joe

Bill Curlee

When I removed the head, I took a picture of the GROUND attached just for this purpose:



You can see the two Black/white striped wires in this pic:




If you look closley you can see the wires and terminal in this pic:




Hope this helps

NJJOE4X4

Bill thanks for those pics now I know what to look for
"black\with white line".

NJJOE4X4

Noid light to both sides of the injectors . Cranked the engine and No light on both sides .no blown fuses. New crank sensor.

3boystoys

Your going to need a decent scanner on the OBD port to trouble shout this, you still don't know of the ECM is seeing anything from any of the sensors (like your new crank sensor).

NJJOE4X4

Yea a scanner is what I`m thinking also, Is there a scanner software that can hook up to a laptop or our smartphone or just look for a tech ll ?If anyone has a cheap scanner that worked for you let me know which one it is.

3boystoys

Get even a cheapy one and plug it in to see if it gets anything at all, I'm guessing your ECM may be MIA. I "assume" you checked ALL the fuses?

I use this on my laptop:
http://www.autoenginuity.com/

You can buy just the GM module if you want.