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GM Bob
GM Bob, ASE Certified Technician
Category: Chevy
Satisfied Customers: 1127
Experience:  30 plus years. experience as GM technician, ASE Master Technician and GM Certified.
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I have a 2010 1500 z71 Silverado and at about 1500 rpm and

Customer Question

I have a 2010 1500 z71 Silverado and at about 1500 rpm and 50 mph under a slight load my truck randomly shudder and the rpm bounce and I can't figure it out any suggestions?
Submitted: 1 year ago.
Category: Chevy
Expert:  GM Bob replied 1 year ago.

Hello my name is ***** ***** I can help.

What have you done so far?

Do you have a scan tool that shows live data?

Customer: replied 1 year ago.
No I don't and I have just done a tune up just plugs and wires but it doesn't do it going down hill or if I get in the gas it stops and it use to only do it when it was hot outside and never in the winter and now it's doing it when it's cooler too
Expert:  GM Bob replied 1 year ago.

Does the RPM jump up or down when this happens?

Can you post your VIN# ***** I can see which engine and trans you have.

This was doing it before you replaced the plugs?

Does it feel like going over speed bumps/ strips?

Customer: replied 1 year ago.
Down about 200 rpm and I'll get the vin shortly
Expert:  GM Bob replied 1 year ago.

Can you keep it running bad long enough to see if the engine light flashes?

Have you ever had it scan for codes.

Most auto part store will scan it for free.

Customer: replied 1 year ago.
No but it has went into power saving mode 3 times where I lose all power and have to shut it off for a few minutes too reset itself
Expert:  GM Bob replied 1 year ago.

When you give me your VIN#

I can check for Special Coverage Adjustment - Throttle Position Sensor Replacement

the throttle position sensor may cause the engine to run rough and cause the malfunction indicator lamp and/or an Engine Reduced Power message to illuminate. If this occurs, it could result in reduced engine power.

Customer: replied 1 year ago.
1gcskte38az197374 and yes it feels just like going over speed strips
Expert:  GM Bob replied 1 year ago.

If you are getting Engine Reduced Power message? I would verify that DTC P2135 is set as Current or in History.

If so have the dealer perform #11273B — Special Coverage Throttle Position Sensor Replacement.

This special coverage is good up to 10 years and 120,000 miles

When they check for codes have tell if any other codes are set.

This may not fix the shudder but will fix the Engine Reduced Power message.

Expert:  GM Bob replied 1 year ago.

Just checking see if you still need help.