Have an HP DesignJet T1100ps error code 86.01 after performing "align printhead" calibration

[Gil9]

Have a DesignJet T1100 sporting error code 86.01

[Valsimot]

When you open the printer window you should see a metal carriage rod use your finger to check it is dry, if yes use a paper towel and damp it with oil and lubricate the carriage rod from left to right as much as you can access with your hand.  The rod must be lubricated for smooth carriage movement.

[Gil9]

Yes, It is well lubed. The carriage assy. moves freely.

[Valsimot]

Does the printer produce any strange noise different from the noise while it was working?

The next step is to clean the encoder strip ( the thin plastic strip above the carriage rod) Use a paper towel and warm water to clean the carriage strip from left to right with 2 fingers holding the towel and strip in between.

[Gil9]

No strange sounds during start up.  Tried  the encoder strip too but no results.

[Valsimot]

Get yourself a service manual for that printer model and follow the troubleshooting steps for that error code. 

[Gil9]

Try the following:
1Switch the Power OFF from the back of the Printer and disconnect the Power cord. Reconnect the power cord and power On the Printer.
2Open the Window and check for any visible obstacles restricting the movement of the Drive Roller. If there is a wrinkled mass of media inside the paper path, lift the Pinch wheels (using the Media Lever) and clear the obstruction.

[Repairatrooper]

If you have service manual, run the diagnostics and check all the carriage components. Could be a failed optical sensor a failing belt, although less likely as you state the carriage moves freely. Failing scan axis motor could also trigger this error.