Common questions

Why did my 1999 Tahoe Suburban not shift?

Why did my 1999 Tahoe Suburban not shift?

Referring to my previous messages, you may recall that on my 1999 Tahoe, the ATC fuse blew twice. This fuse evidently protects the so-called “encoder motor” that shifts the transfer case from 2 Hi to 4Hi, etc. I concluded that the failure to shift was the fault of this shift motor.

How does the shifter work on a Chevy Tahoe?

The shifter motor is controlled by the Transmission Control Module (TCM). when you call for 2WD, 4WD, etc., the TCM tells the shifter motor to rotate that stub shaft to engage couplings, etc. that I imagine control splined shift collars, etc.

What’s the difference between 4Lo and 4HI in a truck?

4Lo: When in 4Lo, your truck is sending torque to all four wheels, but in the low range. It’s also beneficial when you need more power for pulling heavy loads at slower speeds or climbing steep grades.

How to shift from 2 wheel high to 4 wheel high?

Shifting from 2H (2 wheel high) to 4H (4 wheel high) mode is easy and can be done while the truck is in gear and moving. Just shift the floor shifter from 2H to 4H and take your foot off the gas pedal for a second.

When did my 2003 suburban 4WD system fail?

When my 2003 Suburban’s 4WD system failed, I was 4 hours from home with my travel trailer! The front axle was halfway engaged, so it produced a gut-wrenching grinding noise during turns for the entire drive home. However, I fixed it myself-and I bet you can, too!

When does my Tahoe shift to 4WD by itself?

At random times my Tahoe will shift into 4wd hi or lo by itself. It happens while driving, or when i first start the vehicle. It takes 20 min of button pushing to get back to 2hi. Clicking this will make more experts see the question and we will remind you when it gets answered.

Shifting from 2H (2 wheel high) to 4H (4 wheel high) mode is easy and can be done while the truck is in gear and moving. Just shift the floor shifter from 2H to 4H and take your foot off the gas pedal for a second.

Referring to my previous messages, you may recall that on my 1999 Tahoe, the ATC fuse blew twice. This fuse evidently protects the so-called “encoder motor” that shifts the transfer case from 2 Hi to 4Hi, etc. I concluded that the failure to shift was the fault of this shift motor.

The shifter motor is controlled by the Transmission Control Module (TCM). when you call for 2WD, 4WD, etc., the TCM tells the shifter motor to rotate that stub shaft to engage couplings, etc. that I imagine control splined shift collars, etc.

Is the 4 wheel drive switch a failure?

The 4 wheel drive switch is an extremely high failure part. i would replace it and you should be ok! hope this info helps! Testimonial: “thanks for the info. ”

How do you put a new shift motor in a Tahoe?

Now, the new shift motor comes with a plastic tab holding it in Neutral position. The owner’s manual tells how to put the transfer case in Neutral so the new shifter motor can be installed, but the mechanic that fixed my Tahoe simply took a wrench and turned the stub shaft until he reached Neutral, and then installed the new shifter motor unit.

Why are my 4 wheel drive lights not working?

The 2HI lights flash a few times and simply goes back to 4HI. It will not go into 4LO either. I tried warming the transfer case area and motors with a heat gun, no luck, Pulled the fuses as suggested above, no luck. Went back out after luch and now the lights on the selector are dead; fuses was blown.

How does a rotary position sensor work on a Tahoe?

A rotary position sensor tells the TCM when the correct function has been selected and the motor stops and the little spring-applied brake holds the shaft in the right place (Drive function). Now, the new shift motor comes with a plastic tab holding it in Neutral position.

Why is my 4WD light not working on my Chevy Tahoe?

There have been about 3 or 4 times it has went out and stayed out for about a day. Then it would come back on. As of this moment now, the Service 4wd light is on. The lights only come on when I start the truck, then all four come on for a couple of seconds then go back out.

Where is the DLC on a Chevy Tahoe?

1. Install jumper wire between DLC terminal 13 and ground, Fig. 25 . The DLC is located under the lefthand side of the instrument panel, right of the steering column. 2. Turn ignition switch to On position. 3. Wait three seconds, then observe transfer case switch status lamps.

How does DTC Flash work on Chevy Tahoe?

If only one DTC is stored in memory, that DTC flashes repeatedly with a three second delay between flash sequences. If more than one DTC is stored in memory, the first DTC flashes once, then the next code is flashed. This sequence continues to flash until the jumper wire is disconnected.

Why is my transfer case not working on my Chevy Tahoe?

While the transfer case motor is energized the transfer case shift control module also energizes the solenoid for the transfer case lock. The motor lock is disabled (locking action released) and free turning of the transfer case motor and sector shaft is then allowed. This DTC detects a short to ground in Motor Feed A or Motor Feed B CKT.

Why are the lights on my car not working?

If the fuse isn’t being powered it may be a bad relay, wiring to the relay or the BCM. If it is the BCM there may be a code stored in memory. Also check the Headlamp relay which is located in the wiring harness junction block.

What kind of car headlights do not work?

General Motors’ GMT400 platform. got a 1999 two door tahoe and the headlights do not work, but the bright lights work fine. i tried new bulbs, new fuses and even got a new control switch. what else can i do? and how? Answered!

Why are there no lights on my 4WD?

2006 silverado 1500. 4×4 would not engage on mine. I would receive service 4wd message on dash and 4wd switch would change light locations randomly. Changed swich and it did not fix the problem.

2006 silverado 1500. 4×4 would not engage on mine. I would receive service 4wd message on dash and 4wd switch would change light locations randomly. Changed swich and it did not fix the problem.

If the fuse isn’t being powered it may be a bad relay, wiring to the relay or the BCM. If it is the BCM there may be a code stored in memory. Also check the Headlamp relay which is located in the wiring harness junction block.

General Motors’ GMT400 platform. got a 1999 two door tahoe and the headlights do not work, but the bright lights work fine. i tried new bulbs, new fuses and even got a new control switch. what else can i do? and how? Answered!

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Ruth Doyle