Cobalt SS/SC no start issue
March 11th, 2016, 8:16 AM
#23
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what you did was split the system in half. We now know the side that ohmed 120 is all good. the open wiring/bad module is somewhere in the other half.
the daisy chain runs in this order...from the dlc to the psm, to the bcm to thevcim to the ebcm
the problem is in that half of the bus
next we go to the next module and do the same thing and repeat until the open leg is found. reconnect the ebcm and unplug the vcim
the pins for the oher modules are
vcim pins 2, 3 then 8, 9
bcm- which contains one of the 120 ohm terminating resistors. connector c2 pins 1, 19 and 2, 20
power steering module pins 4, 5 and 1, 2
dlc -where you first started pins 14, 6
post the results
the daisy chain runs in this order...from the dlc to the psm, to the bcm to thevcim to the ebcm
the problem is in that half of the bus
next we go to the next module and do the same thing and repeat until the open leg is found. reconnect the ebcm and unplug the vcim
the pins for the oher modules are
vcim pins 2, 3 then 8, 9
bcm- which contains one of the 120 ohm terminating resistors. connector c2 pins 1, 19 and 2, 20
power steering module pins 4, 5 and 1, 2
dlc -where you first started pins 14, 6
post the results
-120 for both 1,19 and 2,20 on the bcm
- OL on 1,2. 120 on 4,5 at the power steering module.
March 11th, 2016, 9:27 PM
#24
something does not seem right. the results contradict themselves. plug everything back in but he vcim connectors and recheck the vcim.
your are removing the connector from the module while doing the test and testing at the connectors not the modules?
below is a handwritten diagram of the circuit.
your are removing the connector from the module while doing the test and testing at the connectors not the modules?
below is a handwritten diagram of the circuit.
Last edited by tech2; March 11th, 2016 at 9:29 PM.
March 11th, 2016, 9:33 PM
#25
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something does not seem right. the results contradict themselves. plug everything back in but he vcim connectors and recheck the vcim.
your are removing the connector from the module while doing the test and testing at the connectors not the modules?
below is a handwritten diagram of the circuit.
your are removing the connector from the module while doing the test and testing at the connectors not the modules?
below is a handwritten diagram of the circuit.
March 11th, 2016, 10:37 PM
#28
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Im going crazy. Everything is plugged in. Now im getting 60 ohms at the dlc, pins 6,14. I positively have an open loop at pins 1,2 at the power steering module connector though. whick makes no sense because those are the same wires. I still have 120 ohms at 4,5 on the power steering.
Last edited by ricklovin93; March 11th, 2016 at 10:40 PM.
March 11th, 2016, 11:01 PM
#29
you will have a open loop at pin 1&2 at the epsm as it leads back to the dlc.
can you confirm what all data says for which modules house the 120 ohm terminating resistors? My info says its the pcm and bcm. maybe its the epsm and pcm?
if your getting 60ohms...does it now start?
can you confirm what all data says for which modules house the 120 ohm terminating resistors? My info says its the pcm and bcm. maybe its the epsm and pcm?
if your getting 60ohms...does it now start?