Throughout the past year, in its On Target newsletter, Ford has conducted a series on its SRS system, Blind Spot Information System and Lane Keep Assist, all of which include helpful information for auto glass technicians when it comes to windshield replacements.
Today we take a general look at Ford’s Lane Keeping System (LKS) and defrost heater. The LKS is an open, momentary-contact switch that grounds the LKS switch-input circuit from the Image Processing Module A (IPMA) when pressed by the driver. The camera windshield defrost heater clears frost and ice from the windshield in front of the IPMA. We explore the LKS in the F-150 for an example of how to install/repair.
Input from the front camera and the air temperature tell the IPMA whether to turn the heater off or on. The heater will come on if the IPMA detects the temperature below 41 degrees. Except with the Ford F-150 Raptor, the defrosting heating element is integral to the windshield and can only be serviced if the windshield is replaced. In the Raptor, the heating element adheres to the inside of the windshield and directly in front of the IPMA camera. The integrity of the wiring, connectors and terminals on the jumper harness must be verified before the heating element is replaced.
An overhead graphic of a vehicle displays in the instrument panel when the LKS is on, and, if lane-keeping mode is selected, arrows are displayed that point toward the lane lines. When the LKS is off, the lane graphics are not displayed on the panel. The color of the lane markings indicates the status of the LKS.
If the system cannot provide lane-keeping assistance, the lane markings will be gray. This indication may mean one of the following: vehicle speed is under LKS activation; too much sun is on the IPMA camera; the vehicle is too close to lane markings, lane markings are either too narrow or too wide, poor lane markings are on the road; the driver is following the vehicle in front too closely; the camera is blocked; the windshield is dirty or damaged; water is standing in the roadway, or other environmental factors exist.
Green indicates the LKS is ready or available to assist. Lane markings are yellow when the system is providing or just provided a lane-keeping aid activation. Red means the system is providing or just provided an activation alert.
For more in-depth repair information, always consult the Ford Workshop Manual at Motorcraftservice.com.