Part 2 0F 2
CLUSTER ILLUMINATION LAMPThe cluster illumination lamps are hard wired in the instrument cluster. When the park or head lamps are turned on, the cluster illumination lamps light. Illumination brightness is adjusted by rotating the headlamp switch panel lamps dimmer thumbwheel (down to dim, up to brighten). The instrument cluster illumination lamps receive battery feed from the panel dimmer circuitry in the headlamp switch through a fuse in the junction block.
The instrument cluster electronic circuitry also monitors the cluster illumination lamp dimming level whenever the park or head lamps are turned on. The instrument cluster electronic circuitry responds by adjusting the dimming level of the odometer Vacuum Fluorescent Display (VFD), and sending dimming level messages over the Chrysler Collision Detection (CCD) data bus network. When the park lamps or headlamps are turned off, the VFD is illuminated at full brightness for improved daylight visibility.
Each of the cluster illumination lamps is located on the instrument cluster circuit board. Each cluster illumination lamp has a replaceable incandescent bulb and bulb holder.
[1][2]CENTRAL TIMER MODULE
Three versions of the Central Timer Module ([1][2]CTM) are available on this vehicle, a base version, a high- line version and a premium 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 [1][2]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 premium version of the CTM is the same as the high-line version, but is used only on models equipped with the heated seat option. The high-line and premium versions of the CTM contain 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.
All versions of the [1][2]CTM are mounted under the driver side end of the instrument panel, inboard of the instrument panel steering column opening. For diagnosis of the base version of the CTM, refer to [1][2]Central Timer Module in the Diagnosis and Testing. For diagnosis of the high-line or premium versions of the CTM or the CCD data bus, the use of a DRB III scan tool and the proper Diagnostic Procedures are recommended. The CTM cannot be repaired and, if faulty or damaged, it must be replaced.
Some of the functions and features that the [1][2]CTM supports or controls include:
- Chimes for the following conditions:
- Headlamps on with ignition off and driver door open warning
- Key in ignition with ignition off and driver door open warning
- ABS lamp warning (if the vehicle is so equipped)
- Airbag lamp warning
- Check engine lamp warning
- Check gauges lamp warning
- Low fuel lamp warning
- Low washer fluid lamp warning
- Seat belt reminder lamp warning
- Transmission oil temperature lamp warning (automatic transmission)
- Central locking
- Courtesy lamp time-out (high-line only)
- Heated seats (premium only)
- Ignition key lamp timer
- Intermittent wipe control
- Enhanced accident response (high-line only)
- Horn chirp upon door lock with RKE (programmable) (high-line only)
- Illuminated entry (high-line only)
- Power door lock control (high-line only)
- Power lock inhibit (high-line only)
- Remote Keyless Entry (RKE) (high-line only)
- Remote radio switches (high-line only)
- Rolling door locks (programmable) (high-line only)
- Speed sensitive intermittent wipe (high-line only)
- Vehicle Theft Security System (VTSS) (high-line only) (if the vehicle is so equipped)
- Wipe after wash (high-line only).
More information on the operation of these [1][2]CTM features and functions that covers the system to which that feature or function applies.
CIGAR LIGHTER
A cigar lighter is standard equipment on this model. The cigar lighter is installed in the instrument panel next to the ash receiver, which is located near the center of the instrument panel, below the radio. The cigar lighter base is secured by a snap fit within the instrument panel.
The cigar lighter knob and heating element unit, and the cigar lighter receptacle unit are available for service. These components cannot be repaired and, if faulty or damaged, they must be replaced.
The cigar lighter consists of two major components: a knob and heating element unit, and the cigar lighter base or receptacle shell. The receptacle shell is connected to ground, and an insulated contact in the bottom of the shell is connected to battery current. The cigar lighter receives battery voltage from a fuse in the junction block only when the ignition switch is in the Accessory or ON positions.
The knob and heating element are encased within a spring-loaded housing, which also features a sliding protective heat shield. When the knob and heating element are inserted in the receptacle shell, the heating element resistor coil is grounded through its housing to the receptacle shell. If the cigar lighter knob is pushed inward, the heat shield slides up toward the knob exposing the heating element, and the heating element extends from the housing toward the insulated contact in the bottom of the receptacle shell.
Two small spring-clip retainers are located on either side of the insulated contact inside the bottom of the receptacle shell. These clips engage and hold the heating element against the insulated contact long enough for the resistor coil to heat up. When the heating element is engaged with the contact, battery current can flow through the resistor coil to ground, causing the resistor coil to heat.
When the resistor coil becomes sufficiently heated, excess heat radiates from the heating element causing the spring-clips to expand. Once the spring-clips expand far enough to release the heating element, the spring-loaded housing forces the knob and heating element to pop back outward to their relaxed position. When the cigar lighter knob and element are pulled out of the receptacle shell, the protective heat shield slides downward on the housing so that the heating element is recessed and shielded around its circumference for safety.
GEAR SELECTOR INDICATOR
An automatic transmission gear selector indicator is standard factory-installed equipment in this model, when it is also equipped with an optional automatic transmission. The mechanical gear selector indicator gives an indication of the transmission gear that has been selected with the automatic transmission gear selector lever.
The indicator housing is mounted to the rear of the instrument cluster housing. The gear selector indicator pointer is easily visible through an opening provided in the front of the instrument cluster mask, and is also lighted by the cluster illumination lamps for visibility at night. This covers only the removal and installation of the gear selector indicator from the instrument cluster.
The gear selector indicator has a spring-loaded pointer that is mechanically actuated by a cable connected to the gear selector indicator driver lever of the gear selector lever mechanism on the steering column. When the gear selector lever is moved the indicator driver lever moves, which actuates the spring-loaded pointer through the mechanical actuator cable. An adjuster mounted on the steering column housing provides a mechanical means of calibrating the gear selector indicator mechanism.
INSTRUMENT PANEL POWER OUTLET
An accessory power outlet is standard equipment on this model. The power outlet is installed in the instrument panel below the cigar lighter and next to the ash receiver, which is located near the center of the instrument panel, below the radio. The power outlet base is secured by a snap fit within the instrument panel. A plastic protective cap snaps into the power outlet base when the power outlet is not being used, and hangs from the power outlet base mount by an integral bail strap while the power outlet is in use.
The power outlet receptacle unit and the accessory power outlet protective cap are available for service. The power outlet receptacle cannot be repaired and, if faulty or damaged, it must be replaced.
The power outlet base or receptacle shell is connected to ground, and an insulated contact in the bottom of the shell is connected to battery current. The power outlet receives battery voltage from a fuse in the Power Distribution Center (PDC) at all times.
While the power outlet is very similar to a cigar lighter base unit, it does not include the two small spring-clip retainers inside the bottom of the receptacle shell that are used to secure the cigar lighter heating element to the insulated contact.
MECHANICAL INSTRUMENT CLUSTER (MIC)
The Ram Truck MIC is available in only one version. The lowline cluster has seventeen indicators lamps and the highline has eighteen indicators lamps. The gauges are positioned with information received by the cluster over the CCD bus from the PCM. Some of the warning lamps are hardwired and the cluster using the CCD bus information controls some. The MIC is hardwired to he [1][2]CTM to provide the warning lamp announcement chimes.
There is a self test available for the cluster that will actuate all the gauges at their calibration points. The test will not run if the cluster sees engine RPM or vehicle speed. This test will light all CCD controlled lamps for verification of lamp operation. It also forces the odometer vacuum fluorescent display (VFD) to perform a segment check. The self test routine can be entered by pushing and holding the trip reset button while rotating the ignition key from the "OFF" to the "ON" position. When the word "chec" appears release the knob and the test will continue.
Starting in the 2000 Powertrain Control Module diagnostic trouble codes (P-Codes) will be displayed in the cluster odometer for the gas trucks only. A diagnostic trouble code display request will be initiated by the JTEC after 3 successive ignition cycles from "OFF" to "RUN" position. The cluster will display the received four digit P-Code for 4 seconds, then display 6 dashes and another P-Code. At the end, when all the P-Codes are done, the cluster will display "DONE" on the odometer.
The cluster will provide bus bias and termination and the engine controller provides a second termination. If the cluster is disconnected the bus will not be biased.
The cluster will be service as an assembly. There will be limited parts available, bulbs and sockets, the front lens, the trip odometer stem cover and the rear cover assembly. No internal parts of the cluster will be serviced.
Normal Operations
At key ON, the cluster will light the low fuel, seat belt, check gauges, and airbag. As the key is turned farther towards the start position, the check engine, ABS (if equipped) and brake warning lamp will illuminate. The (VFD) will indicate the mileage stored inside the cluster. If there is a bus failure and the cluster cannot receive distance pulses from the engine controller, the cluster will display the last mileage stored until the ignition is turned OFF. If the cluster is receiving bus messages but is unable to display odometer information because of an internal failure, the odometer display will be blank. Dimming is handled by the potentiometer that controls instrumentation illumination. Also, if there is a CCD bus failure, "no bus" will be displayed on the odometer 20 seconds after the vehicle is started.
Lamps (Hardwired)
The following lamps are hardwired in the cluster and are not part of the self-test.
Full Time 4WD
Seat Belt
ABS (amber)
High Beam
Left Turn Signal
Right Turn Signal
Security (if equipped)
Low Wash
Wait to Start
Lamps (CCD)
The cluster via CCD messages controls the following lamps. They are actuated during the selftest procedure.
ABS lamp
Brake Warning
Low Fuel Warning - Internally Controlled by the
Cluster not CCD
Airbag
Upshift (if equipped)
Check Engine
Check Gauges
Cruise Control Lamp
Trans Temp
O/D OFF (if equipped)
Water in Fuel
Maintenance Required (5.9 Heavy Duty Only)
NOTE: THE SEAT BELT AND LOW WASHER SWITCH AND BRAKE WARNING LAMP ARE HARDWIRED TO THE CLUSTER. THE CLUSTER THEN DECIDES IF THE LAMP SHOULD BE ILLUMINATED.
DIAGNOSTICS
Gauges
The instrument cluster will not store any DTCs. Because the engine controller PCM gathers all the gauge information and sends it to the cluster via the bus, it is the controller's responsibility to monitor these inputs and store DTCs for them. For this reason the first item to be checked regarding a gauge problem (except oil pressure) should be the engine controller for any DTCs relating to the gauge in question.
There are DTCs associated with all the gauges except for the oil pressure gauge. When diagnosing gauges, the input that is used for the gauge message (fuel level sender for example) must be valid. Because of OBD II requirements, most of the information used for monitoring the OBD II system happens to be the same information used by the controller to formulate the gauge bus messages. OBD II Requirements State that the fuel level sender must be checked for rationality. This includes determining if the sending unit voltage is too high or too low or if the voltage hasn't changed over time. If the PCM has determined that the sender information isn't valid, it will send a diagnostic trouble code. The presence or absence of the fuel level sending code in the PCM is and important factor to determine whether a fuel gauge problem is in the sending unit or the cluster.
The same situation is used in all cluster diagnostics related to gauge operation with the exception of the oil pressure gauge. OBD II requirements do not include oil pressure monitoring. Therefore, oil pressure diagnostics would dictate that a mechanical oil pressure gauge be attached to the engine for absolute verification of oil pressure readings.
Hard Wired Lamps
The cluster contains several hard wired lamps described earlier. These lamps are set up in two configurations. Either the cluster supplies power and ground is supplied by the circuit being monitored or the lamp is supplied ground by the cluster and power comes from a module or other device. Refer to the schematic for the specific details on the lamp in question. Verification of the bulb filament may be required in cases of an inoperative lamp. This will require removal of the cluster and the bulb in question.
NOTE: ALL RED WARNING LAMPS EXCEPT THE WAIT TO START LAMP ARE LIGHT EMITTING DIODES (LED) LED'S ARE NOT REPLACEABLE, IF DEFECTIVE THE INSTRUMENT CLUSTER MUST BE REPLACED.
CCD Controlled Lamps
The cluster contains several CCD controlled lamps as described earlier. These lamps are part of the diagnostic self-test. When entering the self-test mode, operation of these lamps can be observed. If the bulb fails to operate during the self-test and the bulb filament is good, the cluster assembly will need to be replaced.
NOTE: A FLASHING SEAT BELT LAMP INDICATES THAT THE AIRBAG WARNING LAMP IS NOT OPERATING PROPERLY.