GMC P1811: Maximum Adapt and Long Shift (6.5L Diesel only)

What Does The GMC P1811 Code Mean?

Conditions for Setting the DTC:

• The engine must be running for greater than 5 seconds.
• The 1-2 and the 2-3 upshifts are greater than 1.25 seconds.
• The 3-4 upshifts are greater than 6.38 seconds.

The above conditions exist for 5 consecutive

What Are The Potential Causes Of The GMC P1811 Code?

Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions:

• A bent terminal
• A backed-out terminal
• A damaged terminal
• Poor terminal tension
• A chafed wire
• A broken wire inside the insulation

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> KAIWEETS Digital Multimeter

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

Technical Service Bulletin PIP5094 for P1811 – General Motors