JBem

Last week we took about a 500 mile drive for a family vacation. Hot some heavy rain on the way there. Next day our Suburban LTZ(2007, 5.3L, 111K) started cranking for a prolonged period. Continued to get worse over a 5 day period.


Then, we packed up and headed home. We were on the highway for about 25 miles and the Stabilitrak/TC service light came on and showed as both systems being off.


Here are the symptoms of the truck and I'm looking for any help I can get.


1. Hard start - DTC P0171/P0174 (lean bank 1/2)


2. When 4WD selector is in "auto", truck displays it is in 4 high. Have to set selector to 2 high manually.


3. Stabilitrak/TC service light on / system off indicator on.


4. Hard shift from 1st - 2nd when Stabilitrak/TC light is on.


Only checks I have done so far are alternator voltage (avg 14.5v) and cleaned the TB. Some of the forums I've checked said could be TPS, fuel pump, BCM, or LAN harness.


Any thoughts?


Thanks!

07subuurban

Maf sensor and brake switch is what I had my dealership switch out along with the fuel pump. No problem so far