Stetz

I have a 2011 Grand Sport that won't start. I jacked it up and had my son hit the starter button while was under the car. The starter selonoid hammers bad. The dealer said the battery is weak so I put in a new battery. Same problem. I installed a new selonoid . same problem. If I put the charger on boost it will hammer a couple times then start. Dealer said the ECM is bad, installed new, picked up the car and two hours later would not start. Same problem. I am sick of spending money and no fix. With starter on the work bench it works fine. It seems like the engage wire on the starter maybe does not have enough juice? Is there a relay that is not working?

VET4LES

Check all the cables for a good connection and corrosion at the ground points. The solenoid connection can come loose. Check it out.

Dano523

So the starter relay is crank relay #43 in the fuse box under the hood.

So power to the starter solenoid via the battery cable to the fuse lock side terminal, threw fuse 30, to the contractor side of crank relay #43 C14, and when the ECM triggers the relay coil, power out of relay #43 A-13 to the starter solenoid to energize it.

Once the starter is energized by the starter solenoid to press the solenoid plunger forward so the starter gears can engage the flywheel, then the starter is pulling it's main power from the battery cable connector on it directly to the battery (the other larger positive cable off the positive battery terminal.


As for checking if the problem is BCM or ECM, multi-meter set to 12 volt, pull the relay, and connect the probes to C13 and A 14 terminal in the fuse block with the relay pulled, plus the clutch in, and hit the starter button. You should see 12 volts between these two terminal for 15 second (amount that the car will turn the starter if the car does not start). If you need to figure out which tabs on the relay are C13 and A14, turn the mulit meter to ohm and find the two tabs that will give a restance reading (will be the coils side of the relay).
Note, if your not getting voltage during the test, pull the fuse block upper section, clean the bottom tabs on the fuse block, and lower tab receptors on the lower fuse blocks harnesses with spray electrical contact cleaner, and reinstall the fuse block to test again to try to weed out if the problem is in these connectors.


Relay #43 is easy to check as well, (relay type 8864), and you can just just swap it around with another 8864 on the fuse block.

So now this leave few items left to check.

Let start with the easy one, and get in the car, and press the starter button and hold it for 10 seconds without touching the clutch pedal to put the car into run mode without the car started. Now press the second button right hand side of the dash until you get to voltage on the DIC. If the voltage is under 12.3 volts, then that is your problem, hence not enough power in the battery to crank the starter over.

Here, it could be a bad battery, the alternator going south (did a write up on how to fix this for $8)/ in fuse link in the alternator to starter bad, or you leaving the car parked for too many days off a battery tender and the car itself draining the battery down in sleep mode.

Easy check for the battery, stick it on a battery tender for a few days, or put a car charger to the battery, and when fully charged, should be around 13.3 volts. Also, with the battery charged, put the car into run mode without the car running, and turn the lights off and off. The voltage on the DIC should read 13.3 with no lights, and only drop down to around 12.8V with the lights on. If the battery checks out fully charge, but the problem is when you drive it, the alternator is not charging the battery back up, then see my write on correcting the alternator, or could be that the 14g fusible link in the cable connecting the alternator to the starter motor has gone south instead.

Next on the list,
The battery cables could be bad, and either needing to be cleaned/replaced, or may be something simple like the end terminals not clean and tight (the negative terminal to the engine block is one of the ones you need to check as well).

Now the fun one, and the problem could be within the fuse block itself. The clips on the block to the relay tabs could be corroded, or even the bar wires that jump from clip to clip in the fuse block could be corroded to the clips. Here, is just a matter of pulling the upper fuse block, pulling the fuse block apart to clean the wires and contact, clean the lower block plug in sockets, and a little dielectric grease goes a long way on making sure that the connections do not corrode again.




So again, need to break the starter down to two parts, with part one the main charge to starter from the large battery cable, then back to the battery via the large ground battery wire to the engine block.

Part two is the high amp charge to the starter solenoid to activate it, and that is coming from the fuse block from fuse 30, then through relay 43 for the power, and the ECM triggering the relay coil itself on a low amperage wires.

As for the ECM being bad to start with, maybe, or maybe not, and the problem sounds more like a wiring gremlin instead (easy enough to solve, since it's the first test in the lot to see if the ECM is making the relay coil circut to trip relay 43 or not to begin with,and if not, then would dare to bank that the problem is in the wires from either the BCM/ECM, to the fuse block, or in the lower fuse block wiring harness itself).

Stetz

Thanks for the reply guys. I found the problem, the ground cable that attaches to the block, the bolt was loose. I took the cable off, cleaned it and put it back on with the bolt tight, now it starts fine no problems at all. I guess I bought a new ECM and solenoid for experence. Thanks a lot, Dan

VET4LES

Dano523

Don't forget new battery as well, since the old one may have been good, but since the engine ground was loose, just not getting fully charged up.

P.S, I would make a call to GM corp to see about getting your money back on Dealer repairs that where not needed/incorrectly diagnosed to begin with (and people wonder why I don't let anyone loose on my car, unless I forced to by gun point (such as recall work that the dealer has to do the work, or it forever stays on the recall list).

Rayzsurfer

Mr91Chucho

I just started to have these issues. I agree with Ray. A picture of where that ground is on the block would be helpful. Thanks.

Dano523

Right above the starter on the motor.

Mr91Chucho

Thank you!