Horn: Description and Operation
INTRODUCTIONAn electric horn system is standard factory-installed equipment on this model.
Horn System
Two horn systems are offered on this model. The standard equipment horn system features a single low-note electromagnetic horn unit, while the optional dual horn system features one low-note unit and one high-note unit.
Each horn system is activated by a switch concealed beneath the driver side airbag module trim cover in the center of the steering wheel. The horn system is connected to a non-switched battery feed so that the system remains functional, regardless of the ignition switch position.
Following are general descriptions of the major components in the horn system. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the horn system.
SYSTEM OPERATION
Horn Relay
The horn relay is a International Standards Organization (ISO) micro-relay The terminal designations and functions are the same as a conventional ISO relay However, the micro-relay terminal orientation (or footprint) is different, current capacity is lower, and the relay case dimensions are smaller than those of the conventional ISO relay.
The horn relay is a electromechanical device that switches battery current to the horn when the horn switch grounds the relay coil. See Horn Relay in the Diagnosis and Testing for more information.
The horn relay is located in the Power Distribution Center (PDC), in the engine compartment. Refer to the PDC label for relay identification and location.
If a problem is encountered with a continuously sounding horn, it can usually be quickly resolved by removing the horn relay from the PDC until further diagnosis is completed.
The horn relay cannot be repaired and, if faulty or damaged, it must be replaced.
Horn Switch
A center-blow, resistive membrane-type horn switch is installed on the back side of the driver side airbag module trim cover in the center of the steering wheel. When the center area of the airbag trim cover is depressed, the horn switch completes a circuit to ground for the coil side of the horn relay. The steering wheel and steering column must be properly grounded for the horn switch to function.
The horn switch is only serviced as a part of the airbag module trim cover. If the horn switch should fail, or if the airbag is deployed, the airbag module trim cover and horn switch must be replaced as a unit.
Horn
The standard single, low-note, electromagnetic diaphragm-type horn is secured with a bracket to the right front fender wheelhouse extension in the engine compartment. The high-note horn for the optional dual-note horn system is connected in parallel with and secured with a bracket just forward of the low-note horn. Each horn is grounded through its wire harness connector and a wiring circuit to a ground splice joint connector, and receives battery feed through the closed contacts of the horn relay.
The horns cannot be repaired or adjusted and, if faulty or damaged, they must be individually replaced.
Central Timer Module
Two versions of the Central Timer Module (CTM) are available on this vehicle, a base version and a high-line version. The base version of the CTM is used on base models of the vehicle. It is also sometimes referred to as the Integrated Electronic Module (IEM). The base version of the CTM combines the functions of a chime/buzzer module, an intermittent wipe module, and an ignition lamp time delay relay in a single unit.
The high-line version of the CTM is used on high-line vehicles. The high-line CTM provides all of the functions of the base version CTM, but also is used to control and integrate many of the additional electronic functions and features included on the high-line models. The high-line version of the CTM contains a central processing unit and interfaces with other modules in the vehicle on the Chrysler Collision Detection (CCD) data bus network.
The CCD data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, reduce internal controller hardware, and reduce component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities.
The horn relay is one of the outputs that the high-line CTM can control. The high-line CTM is programmed to energize or de-energize the horn relay in response to certain inputs from the Vehicle Theft Security System (VTSS) and the Remote Keyless Entry (RKE) system. Refer to Body and Frame/Locks/Power Locks for more information on the RKE system. Refer to Accessories and Optional Equipment/Anti-Theft/Security Systems for more information on the VTSS.
Both versions of the CTM are mounted under the driver side end of the instrument panel, inboard of the instrument panel steering column opening. Refer to Instrument Panel, Gauges and Warning Indicators/Audible Warning Device/Central Timer Module Replacement for the service procedures.
For diagnosis of the high-line version of the CTM or the CCD data bus, the use of a DRB scan tool and the proper Diagnostic Procedures are recommended. The CTM cannot be repaired and, if faulty or damaged, it must be replaced.