Transmission not shifting correctly

I Have a 2006 Chevy Tahoe Z71 4X4
It’s currently not taking off in drive. I have to use 1gear then move up to 2nd then 3rd. Once i build up a little speed, Drive position will catch but soon as i press the brake to slow down Drive stops pulling and i have to go to lower gears. The fluids are full. I did a computer check at Advance Auto. It showed TPS and Oxygen sensor. Is it time to replace this transmission ??

If all of the gears work when you manually shift the gears, I don’t think the transmission needs replaced. That sounds more like a sensor issue than a mechanical failure. Did you replace the TPS? That might not be the problem, but the transmission shifting is controlled electronically and will use throttle position as one of the inputs to determine when to shift.


If there is a problem with the TPS (Throttle Position Sensor) it might be fixed by spraying electronic contact cleaner into it and working it through its range of motion many times. Or it could just be connection problem.

Thanks so much, I’ll try that first.

They said Tire Pressure Sensor ?
I’m going to another shop today to make sure exactly what codes are showing ?

Get the actual codes, which will be a P followed by four numbers. Don’t ever rely on a parts clerk’s interpretation of what the codes mean.

A TPMS error would most likely not show up on the scanner they’re using, and would illuminate the TPMS light, not the check-engine light even if it did. A TPS error is much more likely to be a throttle position sensor.


Ok thanks so much, I’ll keep you posted.

Well, that’s different!

If you post here the actual codes (P----) we can get some idea of what they might mean. Also you can Google them. Best of luck.

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You might have to ask for two scans to be done: one of engine, one of transmission.

Ah, I thought you meant throttle position sensor. I’d take it to a good trans shop. They’ll have a code reader than can pull transmission codes. It may be a shift solenoid or something that needs replaced. Trans should be ok internally if all of the gears work with no slipping.

Assuming you didn’t get a throttle position code. Like shadow said, post the code numbers. Autozone folks like to sell stuff you don’t need sometimes.

Here are the recent codes I just got a few minutes ago and I drove the truck 30 miles one way and back shifting manually and it worked well even in drive. But the mechanics at the store said that grinding sound in 2nd gear means the transmission is going out :man_shrugging:t5: I am not a car person and all the shops around here are booked solid :cry:

The code means that there is a problem with the heater element circuit of the heated oxygen sensor. The control module monitors how long it takes the sensor to warm up and start sending an adequate signal. The code is triggered when the sensor is taking too long to warm up. Water getting inside the heated oxygen sensor connector can cause the heated oxygen sensor fuse to blow. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. If the sensor and connector are OK, replacing the O2 Sensor 1 usually takes care of the problem.

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Fixing the o2 sensor will be a waste of money, it won’t fix the transmission issues

Fix the transmission first, or get rid of the truck.


I’ll fix it :rofl:

I don’t think oreilly or the zone have a scan tool that can retrieve trans codes…,Apparently. If it won’t shift on its own, there ought to be a code stored other than a code related to the oxygen sensor. Need to take it to a good trans shop (or any mechanic with a GOOD scan tool) and see what other codes are present. I guarantee, on a 2006, there’s another code present if the trans won’t shift on its own. GM went to electronically controlled transmissions around 1994.

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Any code reader/scanner can retrieve transmission DTC’s.


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An 06 Tahoe has a 4l60e. I assume you have avg miles? 150-175k?