2002 Yukon XL Won't Shift into 4HI or HLO

Asked by loger2001 Dec 02, 2018 at 12:29 AM about the 2002 GMC Yukon XL 1500 SLT

Question type: Maintenance & Repair

My 2002 Yukon is stuck in 2HI and the cab switch just blinks when I try to
switch into 4Hi, 4Lo, or Auto. I don't get the clunk. I've already replaced the
front actuator as well as the switch in the cab. I am getting 12V to the
actuator although I can't say for sure that it's engaging. The 4WD fuse also
tested fine.

I have now turned my attention to the transfer case motor. I am getting 5
volts to the green and brown/white going to the motor and the ground seems
to be find as well. I tried to backprobe the brown/white wire so I could test for
a voltage difference when I switch into 4Hi or 4Lo. What happens however is
that my backprobe reads 5 Volt when the connector is unplugged from the
motor but when I attached the wiring harness to the motor and test voltage
(grounding to the battery) I can zero. I have no idea what this means, might
there be a short in the motor?

I appreciate any insights!!

6 Answers

356,485

Maybe the transfer case is the problem.

2 people found this helpful.
262,325

That's signal voltage from the GEM so it knows what position the shift motor is in, 4HI, 4LO, 2WD or AUTO. Transfercase shift motors are a common failure on just about everyone that uses electronic shifting. Sometimes you can get the motor to run if you tap it with a small hammer (or rock it stuck off road) while someone hold the 4HI button and it might run a time or two, I had to replace that motor on both a Ford Bronco and a Chevy Tahoe that I have owned.

1 people found this helpful.

Thank you, I'll get under it again and see if tapping changes things.

I tried tapping the shift motor and it didn't change anything. Before I replaced the shift motor I shifted it to N successfully which was a good sign? Regardless, I replaced the motor and seemed to successfully shift into 4HI once afterwords, but pretty quickly something happened and the Service 4WD light came on. Now I don't even get an indicator light on the button panel. I am guessing I have a more serious problem?

262,325

You might want to check the harness right where it comes out of the floor, I have seen a few rigs that have had to much wire flex and caused intermittent connection problem or a bad ground supply, if it's not there then you should take it to a shop you trust, tell them what you have done so far. Who knows it could just be a bad relay.

1 people found this helpful.

Thank you tennisshoes. I replaced all the brake lines a few months ago and it's possible I disturbed the wiring harness. I'll take a look.

Your Answer:

Yukon XL

Looking for a Used Yukon XL in your area?

CarGurus has 239 nationwide Yukon XL listings starting at $8,995.

Postal Code:

GMC Yukon XL Experts

  • #1
    MikeDaGeek
    Reputation
    4,490
  • #2
    TK76
    Reputation
    670
  • #3
    G A Arne
    Reputation
    620
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Chevrolet Suburban
12 Great Deals out of 227 listings starting at $4,995
Used GMC Yukon
7 Great Deals out of 332 listings starting at $5,499
Used Chevrolet Tahoe
7 Great Deals out of 462 listings starting at $508
Used Cadillac Escalade ESV
3 Great Deals out of 81 listings starting at $8,999
Used Ford Expedition
12 Great Deals out of 390 listings starting at $4,911
Used Cadillac Escalade
4 Great Deals out of 210 listings starting at $6,499
Used GMC Sierra 1500
52 Great Deals out of 4,711 listings starting at $6,400
Used Lincoln Navigator
4 Great Deals out of 140 listings starting at $8,800
Used GMC Sierra 2500HD
6 Great Deals out of 742 listings starting at $3,995
Used Chevrolet Silverado 1500
83 Great Deals out of 6,705 listings starting at $3,000
Used Ford F-150
73 Great Deals out of 6,572 listings starting at $2,995
Used Toyota Sequoia
79 listings starting at $4,995
Used Chevrolet Silverado 2500HD
6 Great Deals out of 821 listings starting at $4,900
Used Dodge Durango
44 Great Deals out of 1,188 listings starting at $4,500

Used Cars for Sale

2021 GMC Yukon XL For Sale
57 listings starting at $68,198
2020 GMC Yukon XL For Sale
57 listings starting at $52,571
2019 GMC Yukon XL For Sale
5 Great Deals out of 42 listings starting at $39,995
2018 GMC Yukon XL For Sale
14 listings starting at $45,962
2017 GMC Yukon XL For Sale
13 listings starting at $37,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.