Before i go to the dealer...

[tiktok4321]

My 08 HyHoe has 277000 miles on it. New ICE about 4 years ago. Refurbished Greenbean about 5 years ago.

Hearing some weird whining under the hood, rarely goes into autostop, avg mpg down to under 14. Greenbean doesn't Ike changing out their lifetime warranty batteries unless there is a DIC notification. In all my years, the Tahoe has NEVER had a DIX notification for hybrid battery.

Any of these symptoms suggest anything else before I go to the dealer and/or replace the hybrid battery?

 

[BG1988]

12v battery a Toxic battery will cause issues in all electrical systems... mine failed and it dropped my mpg to 11-13mpg about as good a 6.0 V8 stall outs etc... Clean all the terminals for the 12v


it would even stall out a running engine in m4 mode it has the variable voltage thing now like it should

Autostop works correctly now

 

[tiktok4321]

Good advice... but the battery and terminals are pretty new and clean. Even had the quick release replaced.

But I do agree that this truck is VERY sensitive to the 12v.

 

[swathdiver]

@RebelBelle

 

[BG1988]

Good advice... but the battery and terminals are pretty new and clean. Even had the quick release replaced.

But I do agree that this truck is VERY sensitive to the 12v.

battery will need to be load tested whats the age?/


makee sure battery cables are seated correctly the post should be about 2-3mm

what is the voltage while driving around should be 14 to 14.2(probing the cig lighter with a muti meter) once the battery is charged to 12.7v....


the current sensor might have an issue also disconnect it and probe it see if you get 14.7(be careful Not too long as it may damage the battery)

close the hood see if it goes into auto stop with in 3-5 seconds

 

[BG1988]

i was doing some probing on a Cold start it uses about 175-200 amps the Voltage goes from 12.7 to 11.5.. this was at night Auto headlights

a normal SUV can go from 12.7 to 10.9 maybe even 10.5 and a cold start it's about 350 amps...


i would check for a faulty wheel speed sensors(or any speed sensor) if it's telling the computer it's over 29mph it will prevent auto stop from working

COLD if it's cold out then the autostop will be disabled below 60F or 50 i think because they don't recharge well when cold this is to prevent completely discharging the battery

 

[tiktok4321]

Checked my 12v. 14.x while running and 12.1 when off as checked throh OBDII module. Didn't sound like it does into the highest gear, but does downshift when I switch to M4.

That whirring under the hood... can't pinpoint it.

Lots of powertrain codes. Mostly for catalytic system.

Cleared to see what comes back. Wife's primary, so I dont get much time in it anymore.

 

[BG1988]

Checked my 12v. 14.x while running and 12.1 when off as checked throh OBDII module. Didn't sound like it does into the highest gear, but does downshift when I switch to M4.

That whirring under the hood... can't pinpoint it.

Lots of powertrain codes. Mostly for catalytic system.

Cleared to see what comes back. Wife's primary, so I dont get much time in it anymore.

12.1 is pretty low i'd say it's eligible to be replaced have it charged at autozone see how far it will go (have them load test it with a print out)

going to the dealer will turn this into a money pit

start with the battery if it needs replacement put it on a tender or disconnect it when not in use... if the voltage is at 12.1 it should peg at 14.7v tell it's close to the correct charge... it should charge by 10 miles or so