Engine will not crank

[soccer1061287]

Ok, I have a 2006 Cobalt SS/SC and I just put a new flywheel and clutch upgrade in it. I finished up the re-assembly today and the engine would not crank over. I realized that I did not have the connectors in the ecm fully seated, so I did so and the information in the DIC changed, but still no crank. Right now, I have the battery disconnected for the night, to see if there were just some random electrons floating around, but I am not overly hopeful that this is it. I also have gone over the engine compartment to see if I left a connector disconnected, but could find none. Has anyone had this problem and what was it? I am convinced it is something simple, but I have not found it yet. Please help if you can.

[goofyguy]

Check all your sensors. You may have removed them and not even realized it like your crank position, cam position, coil packs and so on.

[TXRLU]

Have you checked all your breakers? Maybe with the ECU upgrade you shorted one out? I had trouble with mine and after a long THREE WEEKS, they found there was a loose ground wire near the ABS area below the Radiator Filler neck. good luck.

[zeebees]

Originally Posted by soccer1061287

Ok, I have a 2006 Cobalt SS/SC and I just put a new flywheel and clutch upgrade in it. I finished up the re-assembly today and the engine would not crank over. I realized that I did not have the connectors in the ecm fully seated, so I did so and the information in the DIC changed, but still no crank. Right now, I have the battery disconnected for the night, to see if there were just some random electrons floating around, but I am not overly hopeful that this is it. I also have gone over the engine compartment to see if I left a connector disconnected, but could find none. Has anyone had this problem and what was it? I am convinced it is something simple, but I have not found it yet. Please help if you can.

Well let's look at things logically...you say it doesn't crank at all? That could mean a couple of things...could be something with the clutch as in you car isn't recognizing that you have the clutch pedal depressed. Otherwise I would guess it's starter related...
But since you are saying you just installed the flywheel and clutch it's going to be either: 1)clutch related. 2)electrical related.

[soccer1061287]

OK, here is an update. I have checked every fuse and switched all the circuit breakers under the hood with known good ones. Still no crank. With the key in the run position, I jump the soloniod on the starter and the engine starts. Go for a drive(short) and put back in barn. Engine does not crank. Checked the clutch engage switch at the pedal and it is hooked up. Searched high and low for a connector that I missed or a loose ground. Nothing. Need a circuit diagram to go any further.

[WopOnTour]

Some things to check:
-Is the Security Lamp FLASHING or on STEADY in your IP with the IGN ON?
-Is the PCM/CONT relay (underhood fuseblock) "clicking" ON when you attempt to crank?
-Check the 30A CRANK fuse in the underhood fuseblock
-Check the 7.5A Clutch/Brake fuse plugged into the BCM (inside center console fuseblock)

The circuit schematic and logic is quite convoluted. The IGN switch is wired to the BCM
It TELLS the PCM to engage the PCM/CONT relay (engaging the starter) which it SHOULD providing the PCM "sees" a valid clutch switch input

HTH
WOT

[soccer1061287]

Originally Posted by WopOnTour

Some things to check:
-Is the Security Lamp FLASHING or on STEADY in your IP with the IGN ON?
-Is the PCM/CONT relay (underhood fuseblock) "clicking" ON when you attempt to crank?
-Check the 30A CRANK fuse in the underhood fuseblock
-Check the 7.5A Clutch/Brake fuse plugged into the BCM (inside center console fuseblock)

The circuit schematic and logic is quite convoluted. The IGN switch is wired to the BCM
It TELLS the PCM to engage the PCM/CONT relay (engaging the starter) which it SHOULD providing the PCM "sees" a valid clutch switch input

HTH
WOT

Security Lamp is not on, but the check engine light is. When engine is started by jumping across starter, the check engine light is off which indicates to me that there are no stored codes. Yes, there is a clicking coming from the underhood fuse block when attempting to crank engine. I checked all fuses in the underhood and interior fuse blocks, finding none blown. I am assuming that with those larg fuses, that there would be a clear indication that it was blown if it were. You mentioned a fuse plugged into the BCM. Is it plugged directly into the BCM or is it in the fuse box that is on the right side kick panel of the center stack? If in the fuse panel, we checked it. If elsewhere, help me locate it because that is likely where the problem is. The clutch switch is closing when the pedal is depressed. I am thinking I may need to bring a tech 2 home from work tomorrow to check things out.

[WopOnTour]

Originally Posted by soccer1061287

Security Lamp is not on, but the check engine light is. When engine is started by jumping across starter, the check engine light is off which indicates to me that there are no stored codes. Yes, there is a clicking coming from the underhood fuse block when attempting to crank engine. I checked all fuses in the underhood and interior fuse blocks, finding none blown. I am assuming that with those larg fuses, that there would be a clear indication that it was blown if it were. You mentioned a fuse plugged into the BCM. Is it plugged directly into the BCM or is it in the fuse box that is on the right side kick panel of the center stack? If in the fuse panel, we checked it. If elsewhere, help me locate it because that is likely where the problem is. The clutch switch is closing when the pedal is depressed. I am thinking I may need to bring a tech 2 home from work tomorrow to check things out.

Tech2? Yes, that would help.You very likely have DTCs set but these would be Type C failures set in the PCM or BCM that wont illuminate the MIL. Plus then you will be able to check the Clutch Switch state as observed by the PCM data.
WAIT!! Sorry I missed you were a Cobalt! (different fuses/relays)

FIRST R&R and visibly and electrically check/test the 10A HVAC/IP IGN fuse in the BCM (yes the BCM is a "smart" fuseblock)

Are you CERTAIN the CRANK relay (NOT THE RUN/CRNK RELAY and sorry the PCM/CONT relay was for the ION) "clicks" when turning the ign sw to CRANK? For now maybe try swapping an identical relay for something non-critical like one of the Wiper relays ..

Recheck your PCM connectors as these are a bit tricky. Remove them , inspect the pins on the PCM side for potential damage (bent pin) then reinstall "levering over" the connector lever ONLY after fully engaging the connector and seeing the lever START to move towards the lock side.

If this is all good then... use the diagram/labeling on the side and bottom of the relay to determine the 2 contact "switch terminals" Then using a test light and a 280 series Metripac probe (so you dont damage the underhood fuseblock) check to confirm ONE of these 2 terminals has B+ on it (hot at all times) otherwise PULL AND RECHECK the 30A CRANK fuse with an ohmmeter (sometimes those J-case maxi-fuses dont "look" blown)

If that's all good
THEN MAKING SURE THE TRANS IS IN NEUTRAL AND THE ENGINE CAN CRANK SAFELY use a 10A fused jumper with male MetriPac 280 series terminals- to "jumper across" those 2 "switch contact" terminals at the fuse block THE ENGINE SHOULD CRANK (If you keep the IGN SW OFF it shouldnt START).

If NOT you either have an open in the circuit from the fuseblock to the S terminal of the starter OR the bussed circuit within fuseblock itself has been damaged.

When you get to that point I can help some more...

WopOnTour

[IMkenNY]

Tech II diagnostic tool to work on cobalt/ Ion .......$5,000

Nice set of Snap-On tools .......................... $10,000

Nice warm well lit garage to work on Cobalt / Ion... $20,000

Help from WopOnTour ........... PRICELESS!!!

[soccer1061287]

Originally Posted by WopOnTour

Tech2? Yes, that would help.You very likely have DTCs set but these would be Type C failures set in the PCM or BCM that wont illuminate the MIL. Plus then you will be able to check the Clutch Switch state as observed by the PCM data.
WAIT!! Sorry I missed you were a Cobalt! (different fuses/relays)

FIRST R&R and visibly and electrically check/test the 10A HVAC/IP IGN fuse in the BCM (yes the BCM is a "smart" fuseblock)

Are you CERTAIN the CRANK relay (NOT THE RUN/CRNK RELAY and sorry the PCM/CONT relay was for the ION) "clicks" when turning the ign sw to CRANK? For now maybe try swapping an identical relay for something non-critical like one of the Wiper relays ..

Recheck your PCM connectors as these are a bit tricky. Remove them , inspect the pins on the PCM side for potential damage (bent pin) then reinstall "levering over" the connector lever ONLY after fully engaging the connector and seeing the lever START to move towards the lock side.

If this is all good then... use the diagram/labeling on the side and bottom of the relay to determine the 2 contact "switch terminals" Then using a test light and a 280 series Metripac probe (so you dont damage the underhood fuseblock) check to confirm ONE of these 2 terminals has B+ on it (hot at all times) otherwise PULL AND RECHECK the 30A CRANK fuse with an ohmmeter (sometimes those J-case maxi-fuses dont "look" blown)

If that's all good
THEN MAKING SURE THE TRANS IS IN NEUTRAL AND THE ENGINE CAN CRANK SAFELY use a 10A fused jumper with male MetriPac 280 series terminals- to "jumper across" those 2 "switch contact" terminals at the fuse block THE ENGINE SHOULD CRANK (If you keep the IGN SW OFF it shouldnt START).

If NOT you either have an open in the circuit from the fuseblock to the S terminal of the starter OR the bussed circuit within fuseblock itself has been damaged.

When you get to that point I can help some more...

WopOnTour

Here is what I know to be true about the relays. First off, I swapped all of the relays that appeared to have something to do with Ign, Crank or PCM with other known good relays. Still no crank. Second, I know that when I turn the key from run to crank, a relay clicks in the underhood fuse block. I have not been able to be actually standing there with my hand on the relay to feel it when the key is turned. I will recheck the PCM connectors, because I did take the PCM out to move the fuse block for access to the trans mount bolts.

You keep mentioning the BCM and fuses in it. Is the BCM a different unit from the fuse block in the center stack. Anything I have done in the car to this point has been in that fuse block. If the BCM is right there or near by and has its own fuses, please set me straight on that. You mention a 280 series Metropack probe. I have a Sears DVOM. Can I use it without damaging anything? Also, can I pull the codes with my SnapOn 2500 series scanner if I do not have the 2005 or 2006 cartridge? I think the latest cartridge I have right now is the 2000. I have heard you can fake the scanner by giving it an earlier year code, but would the OBD II codes be the same for a 2000 as a 2006 and what body code, engine code and year code woould I use to do that. I am just concerned that with the monster layoffs that we (GM) will be announcing tomorrow, that I will not be able to get a tech 2 today.

Thx, Mike