black box
Race Director
Joined: Dec 2013
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BCM with some fused in it in the center of it, Bose amp will be to the left of the BCM, and the vet has an two extra fuse/relay blocks below and to the right of the BCM with covers on them (that you have to pull the covers to get to the fuses/relays in the blocks).
Last edited by Dano523; Jan 12, 2016 at 04:34 PM.
Thread Starter
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black box
ok , thanks again dano523 , its to te right of the blue connector on the right, Im checking everything trying to get this 06 to start
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,628
The lower and the right hand fuse box with covers should have nothing in them keeping the car from starting.
So , is the DIC telling you something like "no fob found" or something else? Also, did you disconnect any wiring harnesses, like the VCIM and now have a break in the GM lan bus wiring? And when you push the start button, what is the car/dash doing?
Circuit Description
When the ignition mode switch is placed in the START position, a discrete input is sent to the body control module (BCM) notifying it that engine start has been requested. The BCM then verifies that the brake pedal or clutch pedal has been depressed with a discrete input from the brake pedal position sensor/clutch switch and that the key fob, with the correct code, is in the vehicle. After this information has been verified the BCM grounds the control side of the RUN/CRANK relay closing the switch side of it and allowing battery positive voltage to flow from the BATT 3 fuse through the RUN/CRANK relay switch, engine control module (ECM) fuse to the battery positive voltage side of the CRANK relay coil. The BCM also sends a high speed GMLAN message to the ECM requesting engine start. The ECM will then verify that the internal mode switch (IMS) is in Park / Neutral or the clutch pedal is fully depressed. After this has been verified the ECM the supplies ground to the control circuit of the CRANK relay closing the CRANK relay switch circuit and allowing battery positive voltage to flow through the STARTER fuse, the CRANK relay switch to the S-terminal of the Starter solenoid cranking the engine. Ground is supplied through the engine block.
So on that note, break it down to if the starter itself on the control lead is seeing power of not to be begin with and the both positive terminal nuts on the starter are tight and not one of the terminals broken off instead. Also to note, you can bump the starter if needed to make sure that it not defective by jumping through crank relay 43.
If no power to the starter control wire when the start button is pushed and the ECM/BCM doing there thing to send power to the starter (the connector that plugs into the starter), then chase it back to the engine fuse box for a break in the control wire there to the starter relay.
On the other side of the coin, is the BCM that has to send the signal to the ECM to request the ecm to start the car in the first place, and that is to trigger the start relay to send power to the starter, much less the starter button working in the first place to send the needed message to start the cycle.
On the BCM side, easy to just chase the problem with a Tech II to look for problems instead.
Hence tell you if the bcm is seeing the starter button push/ the gm lan not having a problem, the ecm and BCM seeing all there requirements to trigger the starter relay in the first place to send power to the starter via the control wire to turn the starter.
Hence if BCM and ECM checks out (and the rest of the needed switches) and is sending the needed command for the ECM to trigger the starter relay in the first place, then you know that the problem is on the mechanical side of the system down line (after the ecm), hence either the starter relay 43, the starter fuse, the starter, or the wiring from the fuse box through the crank relay 43 to starter instead.
Note: look at crank 1of 2 below, to understand how the starter gets power once the ECM has triggered crank relay 43 to send power to the starter via line C13/A14 out of the ecm. Crank 1 or 2 is all the items needed by the BCM before it will send the signal to the ECM to trigger the starter in the first place (trigger the crank relay on lines C13/A14). Hence if you jump crank relay 43 (C14/A13) and the starter spins, then you know that the problem in back in the BCM/ECM level instead.
Schematics is you need them,
http://www.mediafire.com/view/dqcsxd...ank_1_or_2.pdf
http://www.mediafire.com/view/s3va8d...ank_2_of_2.pdf
http://www.mediafire.com/view/x4dg5d...4/charging.pdf
So , is the DIC telling you something like "no fob found" or something else? Also, did you disconnect any wiring harnesses, like the VCIM and now have a break in the GM lan bus wiring? And when you push the start button, what is the car/dash doing?
Circuit Description
When the ignition mode switch is placed in the START position, a discrete input is sent to the body control module (BCM) notifying it that engine start has been requested. The BCM then verifies that the brake pedal or clutch pedal has been depressed with a discrete input from the brake pedal position sensor/clutch switch and that the key fob, with the correct code, is in the vehicle. After this information has been verified the BCM grounds the control side of the RUN/CRANK relay closing the switch side of it and allowing battery positive voltage to flow from the BATT 3 fuse through the RUN/CRANK relay switch, engine control module (ECM) fuse to the battery positive voltage side of the CRANK relay coil. The BCM also sends a high speed GMLAN message to the ECM requesting engine start. The ECM will then verify that the internal mode switch (IMS) is in Park / Neutral or the clutch pedal is fully depressed. After this has been verified the ECM the supplies ground to the control circuit of the CRANK relay closing the CRANK relay switch circuit and allowing battery positive voltage to flow through the STARTER fuse, the CRANK relay switch to the S-terminal of the Starter solenoid cranking the engine. Ground is supplied through the engine block.
So on that note, break it down to if the starter itself on the control lead is seeing power of not to be begin with and the both positive terminal nuts on the starter are tight and not one of the terminals broken off instead. Also to note, you can bump the starter if needed to make sure that it not defective by jumping through crank relay 43.
If no power to the starter control wire when the start button is pushed and the ECM/BCM doing there thing to send power to the starter (the connector that plugs into the starter), then chase it back to the engine fuse box for a break in the control wire there to the starter relay.
On the other side of the coin, is the BCM that has to send the signal to the ECM to request the ecm to start the car in the first place, and that is to trigger the start relay to send power to the starter, much less the starter button working in the first place to send the needed message to start the cycle.
On the BCM side, easy to just chase the problem with a Tech II to look for problems instead.
Hence tell you if the bcm is seeing the starter button push/ the gm lan not having a problem, the ecm and BCM seeing all there requirements to trigger the starter relay in the first place to send power to the starter via the control wire to turn the starter.
Hence if BCM and ECM checks out (and the rest of the needed switches) and is sending the needed command for the ECM to trigger the starter relay in the first place, then you know that the problem is on the mechanical side of the system down line (after the ecm), hence either the starter relay 43, the starter fuse, the starter, or the wiring from the fuse box through the crank relay 43 to starter instead.
Note: look at crank 1of 2 below, to understand how the starter gets power once the ECM has triggered crank relay 43 to send power to the starter via line C13/A14 out of the ecm. Crank 1 or 2 is all the items needed by the BCM before it will send the signal to the ECM to trigger the starter in the first place (trigger the crank relay on lines C13/A14). Hence if you jump crank relay 43 (C14/A13) and the starter spins, then you know that the problem in back in the BCM/ECM level instead.
Schematics is you need them,
http://www.mediafire.com/view/dqcsxd...ank_1_or_2.pdf
http://www.mediafire.com/view/s3va8d...ank_2_of_2.pdf
http://www.mediafire.com/view/x4dg5d...4/charging.pdf
Last edited by Dano523; Jan 12, 2016 at 09:06 PM.
