Crank, no start, low voltage

Tiny
ROBOTECH2
  • MEMBER
  • 2003 GMC SIERRA
  • 6.6L
  • V8
  • 4WD
  • AUTOMATIC
  • 160,000 MILES
No or low voltage to cab. No interior lights, power windows and door locks not operating. Engine cranks and fires but shuts off immediately. DTC's are P 1626 and U 1026. Anti theft system is active and not getting fuel enable signal. The u 1026 code says no communication with ATC. Could my BCM be bad and if so what might be the cause? Batteries and alternator are new and charge is 100%.
Thursday, April 25th, 2019 AT 4:35 AM

5 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good morning,

It sounds like the fuse block may not be allowing voltage to the interior.

Yes, the BCM controls the anti-theft but the BCM needs power to work.

Test for power to the under hood fuse block as well as the ignition switch.

Roy
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Thursday, April 25th, 2019 AT 5:03 AM
Tiny
ROBOTECH2
  • MEMBER
  • 3 POSTS
I have power at the fuse block. And I have power at the fuse block in the cab.
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Thursday, April 25th, 2019 AT 5:26 AM
Tiny
ROBOTECH2
  • MEMBER
  • 3 POSTS
Maybe a grounding issue?
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Thursday, April 25th, 2019 AT 5:27 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
No, it is a power issue.

Check the ignition switch voltage.

Roy
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Thursday, April 25th, 2019 AT 5:39 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Did you respond? I got a notification but no response listed.

Roy
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Thursday, April 25th, 2019 AT 9:19 AM

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