Manual Override

WARNING: This page is about a different car, the 2010 Ford Pickup, 2010 Ford F550 Super Duty, 2010 Ford F450 Super Duty, and 2010 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

The AUTO hublocks have a manual override selector dial, which, when turned to the LOCK position, will keep the hublocks locked (through the dial) at all times, regardless of the position of the instrument panel MSS . (Always set both hublock dials to the same position.) If the hublock dials are manually turned from the AUTO to the LOCK position, and the high vacuum level is applied to the hublocks (by switching the MSS from 2WD to 4X4 High or 4X4 Low), the hublocks will be locked through the dial as well as through the internal spring mechanism. In this case, turning the hublock dials back to the AUTO position will leave the hublocks in (spring) locked mode until the lower vacuum level is applied to the hublocks (by switching the MSS from 4X4 High or 4X4 Low to the 2WD ). (This is not an issue if the hublock dials have been in the AUTO position and the MSS has been switched from 4X4 High or 4X4 Low to 2WD at least once.) Alternatively, the hublock mechanism can be reset to free mode at any time by turning the hublock dial from AUTO to LOCK to AUTO at least 2 times.

Electronic Shift-On-The-Fly (ESOF) Automatic Hublock Operation

ELECTRONIC SHIFT-ON-FLY (ESOF) AUTOMATIC HUBLOCK OPERATION CHART

Hublock Operational State	Hublock Dial Switching Procedure
"Locked" Position - Manual Override	Switch the hublock dial to LOCK
"Free" Mode (for Troubleshooting or Recreational Towing)	Switch the hublock dial from AUTO to LOCK and back to AUTO to least 2 times
"Automatic" Operation via Electronic Shift-On-The-Fly (ESOF)	Switch the hublock dial to AUTO
"Automatic" Vacuum Control with Mode Select Switch (MSS) in 4X4 High or 4X4 Low	NOTE: This cycle will always be completed and cannot be interrupted by switching the MSS to 2WD . If vehicle speed goes below 8 km/h (5 mph) during the 45- second cycle and the MSS remains in 4X4 High or 4X4 Low, the locking cycle will repeat.Switch the hublock dial to AUTOPulse Vacuum Hublock (PVH) solenoid activated for 45 seconds/vacuum at knuckle is 216 mm (8.5 in) Hg or more.PVH solenoid vents for 6 seconds.
"Automatic" Vacuum Control with MSS in 2WD	NOTE: Switching the MSS to 4X4 High or 4X4 Low will interrupt this cycle. Switch the hublock dial to AUTOPVH solenoid activated for 15 seconds/vacuum at knuckle is 150 to 180 mm (5.9 to 7.1 in) Hg.