2006 Trailblazer: Single crank then whiz out out, 58 error codes intitially, U1000 others after code clear

[TampaTechnician 0]

No observed haywire stuff with the electronics. No start situation came about recently. Apparently as of yesterday it was possible to keep trying the key with it and eventually could get to start. Today that never happened.

 

The effect when trying to start is interesting, a great many times the key was turned today and always the same effect: a single solid crank then it like just fizzles out after a few seconds. Never heard one sound quite like it.

 

Fuel pressure and flow at the test valve good. Spark good. Fuses good. Voltage good. Fuse panel looks pristine. No obvious rough looking wiring harnesses or the like (Florida car). Everything seemed to check out in the fuse panel for that relay, as well as the pin-ins of the starter.

 

Threw the BlueDriver on there and whammo 58 error codes. All kinds of stuff like 'everything' it seemed like was bad, AC system, speed sensors, stereo circuits, on and on codes (which ironically not too many at all jumped out that looked like theyd have anything to do with the no start situation even stood out much from the list).

 

Which struck me as its like theres a such a capable module in there, on the fritz to the effect of generating false codes like everywhere it could.

 

Reset the codes, rescan (without being able to start it properly), now its displaying:

 

PO462 Fuel Level Sensor A Circuit High     

 

C0035 & C0045 LF & LR wheel speed sensor circuit malfunction

 

U1000 Class 2 Data Link Malfunction

 

B2961 Status HISTORY key in ignition circuit malfunction

 

U1000 all about BCM, fixes in BlueDriver database are 1. Replace BCM, 2. See other network related codes for more information

 

B2961 fixes are: 1. Repaired ignition switch harness, 2. Replace ignition switch, 3. Replaced BCM.

 

-At this point starting asking about noted malfunctions with the sorts of things the BCM can malfunction, and none of the 'crazy stuff' going on with lights or etc, BUT the radio just doesnt work (unknown why yet currently).

 

Everything appeared fine in the wires could see.

 

Cheap fix attempt being the ignition switch, swapped that and same thing.

 

Which the final reported fix in the BD database is "replace BCM".

 

Of course the database isnt all seeing and knowing.

 

And maybe the -actual- no start ordeal is something 'minor' overlooked, and there just so happens to be all the 'haywire' going on with the codes.

 

Well the 'apparent haywire' thing has at least been a thing. The codes now that would be ignition crucial 1 isnt a module and if changing it doesnt fix it then theres its wiring harness OR change the BCM, from there changing the BCM or wiring related to / other problems with other modules is where 'everything' points to. With no apparent indicators of other module malfunctions.

 

And at that point it was time to stop the clock on the job, do more research so here I am.  :)

 

 

 

 

[TampaTechnician 0]

Heres some of the intial codes, too many to list:

 

B camshaft position, Ho2s heater control circuit bank 1 sensor 1, manifold absolute pressure, o2 sensor heater, air system incorrect flow, evap system leak detected, fuel level sensor circuit highm fan 1 control unit, fan speed high, idle control system RPM, evap system high purge flow, P1400 dirty throttle body, speed sensor circuit codes malfunctions, steering position sensor circuit malfunction, pwn delivered torque malfunction, backup lamps control circuit malfunction, headlapmp control circuit malfunction, (and a bunch more like this all strike me as expected wackyness a BCM would cause but they just never noticed they said), lost communication with Convenience COntrol System, antenna ground malfunction...

 

okay these two may be relevant to the end bit of the OP: Losty communications with the Body Multiple Control System, and Lost comms with Engine Control systems.

 

Note many or most of the codes reported had "HISTORY" at the beginning of the descriptions.

[chem_man 3]

The first thing I would do is to clean all the ground connections including the battery cable to battery terminal connections.  That many DTCs points to something common - like the ignition switch (which you already changed) or battery.  You also want to get your battery load tested to make sure it does not have a bad cell, and then make sure it is completely charged before trying to start it again.  While you have the battery out, check the battery cables to make sure that they are not corroded internally by looking for green stuff near the cable ends.

 

While you are at it, have your alternator tested to make sure it is not faulty in terms of a bad diode or that it is putting out more than 20 mV AC ripple on the DC voltage.