Part 3 of 3

TURN SIGNAL CANCEL CAM
The turn signal cancel cam is concealed within the steering column below the steering wheel. The turn signal cancel cam consists of two lobes on a molded plastic ring that is snapped into the lower hub of the clockspring rotor. The clockspring mechanism provides turn signal cancellation as well as a constant electrical connection between the horn switch, driver airbag, speed control switches, and remote radio switches on the steering wheel and the instrument panel wire harness on the steering column. The housing of the clockspring is secured to the multi-function switch mounting housing on the steering column and remains stationary. The rotor of the clockspring, including the turn signal cancel cam lobes rotate with the steering wheel.

The turn signal cancel cam is serviced as a unit with the clockspring and cannot be repaired. If faulty or damaged, the entire clockspring unit must be replaced. (Refer to RESTRAINTS/CLOCKSPRING - REMOVAL).

The turn signal cancel cam has two lobes and is secured to the lower hub opening of the clockspring rotor. When the turn signals are activated by moving the multi-function switch control stalk to a detent position, a turn signal cancel actuator is extended from the inside surface of the multi-function switch housing toward the center of the steering column and the turn signal cancel cam. When the steering wheel is rotated during a turning maneuver, one of the two turn signal cancel cam lobes will contact the turn signal cancel actuator. The cancel actuator latches against the cancel cam rotation in the direction opposite that which is signaled. In other words, if the left turn signal detent is selected, the lobes of the cancel cam will ratchet past the cancel actuator when the steering wheel is rotated to the left, but will unlatch the cancel actuator as the steering wheel rotates to the right and returns to center, which will cancel the turn signal event and release the control stalk from the detent so it returns to the neutral OFF position.

DOOR AJAR SWITCH
The door ajar switches are integral to the door latches on each door. The switches close a path to ground for the Central Timer Module (CTM) when a door is opened, and open the ground path when a door is closed.

The door ajar switches cannot be repaired and, if faulty or damaged, the door latch unit must be replaced.

The door ajar switches close a path to ground for the Central Timer Module (CTM) when a door is opened, and opens the ground path when a door is closed. The passenger side front door and both rear door ajar switches are connected in a parallel-sense circuit between ground and the CTM, while the driver side front door ajar switch is connected in series between ground and the CTM to provide a unique input. The CTM reads the switch status through an internal pull-up, then sends the proper switch status messages to other electronic modules over the Programmable Communications Interface (PCI) data bus network. The door ajar switches can be diagnosed using conventional diagnostic tools and methods.