Part 1B

Stored Codes
Airbag codes are automatically stored in the ACM's memory as soon as the malfunction is detected. The exception is the "Loss of Ignition Run Only" code which is an active code only.

A "stored" code indicates there was an active code present sometime. However, the code currently may not be present as an active code, although another active code could be.

When a trouble code occurs, the airbag warning lamp illuminates for 12 seconds minimum (even if the problem existed for less than 12 seconds). The code is stored, along with the time in minutes it was active, and the number of times the ignition has been cycled since the problem was last detected.

The minimum time shown for any code will be one minute, even if the code was actually present for less than one minute. Thus, the time shown for a code that was present for two minutes 13 seconds, for example, would be three minutes.

If malfunction is detected a diagnostic trouble code is stored and will remain stored as long as the malfunction exists. When and if the malfunction ceases to exist, an ignition cycle count will be initiated for that code. If the ignition cycle count reaches 100 without a reoccurrence of the same malfunction, the diagnostic trouble code is erased and that ignition cycle counter is reset to zero. If the malfunction reoccurs before the count reaches 100, then the ignition cycle counter will be reset and the diagnostic trouble code will continue to be a stored code.

If a malfunction is not active while performing a diagnostic test procedure, the active code diagnostic test will not locate the source of the problem. In this case, the stored code can indicate an area to inspect.

If no obvious problems are found, erase stored codes, and with the ignition "ON" wiggle the wire harness and connectors, rotate the steering wheel from stop to stop. Recheck for codes periodically as you work through the system. This procedure may uncover a malfunction that is difficult to locate.

Airbag Trouble Codes
The airbag control module may report any of the following diagnostic trouble codes. For the following codes, replace the control module (ACM) even if set intermittently:

- ACM ACCELEROMETER
- ACM OUTPUT DRIVER CIRCUIT OPEN
- ACM INTERNAL DIAGNOSTIC CODE #1
- ACM INTERNAL DIAGNOSTIC CODE #2
- ACM STORED ENERGY
- ACM OUTPUT DRIVER

For these codes, refer to the appropriate diagnostic procedure:
Testing and Inspection

Cluster Message Mismatch
Driver Squib Circuit Open
Driver Squib Circuit Shorted
Driver Squib Circuit Shorted to Battery
Driver Squib Circuit Shorted to Ground
Loss of Ignition Run Only
Loss of Ignition Run/Start
No Cluster CCD Message
No CCD Communication
Passenger Squib Circuit Open
Passenger Squib Circuit Shorted
Passenger Squib Circuit Shorted to Battery
Passenger Squib Circuit Shorted to Ground
Warning Lamp Open/Shorted

Enhanced Accident Response (Highline Only)
If the Airbag Control Module (ACM) deploys the airbags, a message is transmitted over the CCD bus to the [1][2]CTM module to unlock the doors. The interior lights will be turned ON 10 seconds after getting zero speed message on the CCD bus.

In addition to unlocking the doors, the lock feature will be disabled for a predetermined amount of time following the deployment. Once the ignition key has been cycled to the "OFF" position, normal operation will resume.

[1][2]CENTRAL TIMER MODULE
The AB RAM VAN has two different body electrical systems, High Line and Base. The High Line utilizes a Central Timer Module ([1][2]CTM) to provide the body features listed below. The CTM was designed to reduce cost, wiring complexity, and improve the system reliable. The CTM 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 information between modules and diagnostic capability using the DRBIII (R). The CTM equipped vehicles can be identified by the sound of a Key-In Ignition CHIME.

The Base AB RAM VAN body system is composed of individual modules. Because the standalone modules do not communicate on the CCD Bus they cannot be diagnosed using the DRB. For concerns about the BASE AB VAN, refer to the appropriate service Procedures. The Base version can be identified by the sound of the Key-In Ignition BUZZER.
Testing and Inspection

The [1][2]CTM provides the following features:
- CCD Bus Communication
- Central Locking Features
- Chime
- Courtesy Lamp Controls/Illuminated Entry
- Enhanced Accident Response
- Intermittent Wiper Delay
- Power Door Locks W/RKE
- Remote Keyless Entry (RKE)
- Speed Sensitive Intermittent Wipers
- Vehicle Theft Security System (VTSS)

The module is located on the left center instrument panel support. It contains a white 18-way and a green 14-way connector.

[1][2]Central Timer Module Diagnostic Trouble Codes
Door Disarm Switch Failure
Door Lock Switch Failure
Door Unlock Switch Failure
Wiper Park Switch Failure
EEPROM Checksum Failure
Internal ROM Test Failure
Central Lock Switch Failure

Chime System
The chime system is built into the [1][2]CTM. The system also supports an external chime request from the instrument cluster. This feature allows the instrument cluster to request a chime from the CTM for gauge problems and tell tale warnings. The CTM chime functions will have priority over the MIC chime requests. There are two chime rates, Low; 50 chimes per minute for reminders and High; 180 chimes per minute for serious conditions that require immediate attention. The high rate chime sounds when the key is left in the ignition and the driver door is open or the headlights are left ON. The low rate chime sounds for any of the other conditions. There is a variable rate feature that allows the chime to sound continuously for the key-in, and headlamp warning, as long as the drivers door is open. The seat belt warning chime is activated for 4 to 6 seconds, and all other chime conditions will activate the chime once at the same time the warning light on the cluster is illuminated.

The chime will sound for the following conditions:

HIGH RATE
- Key in Warning ignition OFF, key in ignition, driver's door open
- Ignition OFF; headlamps ON, driver's door open

LOW RATE
- Seat belt warning-6 seconds after key ON (6 to 8 chimes) or until seatbelt is buckled
- Airbag lamp illuminated (3 times after prove-out)
- ABS lamp illuminated (2 chimes after prove-out if equipped)
- Check engine lamp illuminated (2 chimes after prove-out)
- Check gauges lamp illuminated (2 chimes)
- Engine Temp-High-when gauge enters red zone (2 chimes)
- Low fuel - when fuel level reaches 118 tank (2 chimes)
- Low washerfluid (2 chimes)
- Transmission Temperature High (2 chimes)

If the ignition switch is turned to the run/start position and the driver's door is closed, then opened, the warning chime is defeated. This allows the doors to be open without the warning chime constantly sounding The [1][2]CTM stays in this mode until the ignition switch is turned to the "OFF" position, then normal function will be restored.

INTERIOR LIGHTING
The illuminated Entry system consist of a maximum of three dome lamps which are located in the front, middle and rear of the head liner. While the vehicle is OFF the illuminated entry feature can be activated in the following ways.
- Whenever a door is opened
- When the vehicle is unlocked with a key
- When the [1][2]CTM receives a valid unlock signal from the RKE transmitter

The illuminated entry will remain ON for 30 seconds after the last door is closed, turn OFF immediately after ignition is turned ON, or turn OFF when the [1][2]CTM receives a LOCK message from the RKE transmitter.

15 Minute Illumination Timeout
If the ignition is OFF and either front door is open, interior illumination will terminate after 15 minutes. If either front door is open and the ignition is turned in the RUN or ACCESSORY position, interior illumination will continue until the ignition is turned OFF. Once the ignition is OFF, if either front door remains open, the 15 minute interior illumination timeout will begin. Note: This timeout feature does not apply to either auxiliary door or the dome lamp switch which are hardwired to the courtesy lamps. The auxiliary door switches are also wired to the [1][2]CTM to operate illuminated entry.

MECHANICAL INSTRUMENT CLUSTER (MIC)
The Ram Van uses a standard MIC in all of it's US vehicles. The cluster has 5 gauges and 15 indicator lamps. The gauges are positioned with information received over the CCD bus. Some of the indicator lamps are hardwired while the cluster uses CCD bus information to control others. The MIC is hardwired to the [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 to their calibration points. The self test will not run if the cluster sees engine RPM or vehicle speed. The 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 pressing and holding the trip reset button while rotating the ignition key from the "OFF" position to the "ON" position. When the word "check" appears release the button and the test will continue.

The cluster will provide bus bias termination and the engine controller provides a second termination, If the cluster is disconnected, the bus will not be biased.

The cluster will be serviced as an assembly. There will be limited parts available, bulbs and sockets, the front lens, the trip odometer system cover and the rear cover assembly. No internal parts of the cluster will be serviceable.

Normal Operation
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 vacuum fluorescent display (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 blink 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.

Lamps (Hardwired)
The following lamps are hardwired in the cluster and are not part of the self-test.
High Beam
Left Turn Signal
Right Turn Signal
Brake (comes ON during self-test)
Low Wash (comes during self-test)
Seat Belt (comes ON during self-test)
Security

Lamps (CCD)
The cluster via CCD messages controls the following lamps. They are actuated during the self-test procedure.
ABS lamps
Airbag
Check Engine
Check Gauges
Cruise Control Lamp
Trans Temp
O/D OFF
Low Fuel Warning - Internally controlled by the Cluster not CCD

NOTE: THE TURN SIGNALS, HIGH BEAM INDICATOR, SEAT BELT WARNING LAMP, LOW WASHER WARNING LAMP, AND BRAKE WARNING LAMP ARE HARDWIRED TO THE CLUSTER.

Diagnostics
Gauges
The instrument cluster will not store any DTC's. 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 DTC's 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 DTC's relating to the gauge in question. There are DTC's associated with all the gauges except for the oil pressure gauge. When diagnosing gauges, the input that is used for 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 requirement 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 an 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 diagnostic 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. The 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 bulb in question.

NOTE: THE BRAKE, TRANS TEMP, CHECK GAUGES, SEAT BELTS AND AIRBAG WARNING LAMPS ARE LED'S, ALL OTHER ARE BULBS. IF ANY LED'S ARE 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.

POWER DOOR LOCKS
The [1][2]CTM controls the door lock actuation assemblies to handle locking and unlocking with the interior door lock switches or the RKE transmitter (key fob). There is also a door lock inhibit feature that prevents the power locking of the doors if the key is in the ignition or the headlamps are ON and the left front door is open. However, the doors can still be locked using the RKE transmitter which allows the engine to run for warm up purposes.

Automatic (rolling) Door Locks
When the doors are closed and the vehicle speed exceeds 15 MPH due to engine power (not just rolling) and all doors are closed, the [1][2]CTM will lock the doors. The vehicle is shipped with the automatic door lock feature disabled, but may be enabled using the DRB.

Door Lock Delay
If the [1][2]CTM receives a signal to lock the doors and one or both of the auxiliary doors (side or rear) are open, the front doors will still lock. Five seconds after both of the auxiliary door are closed, the CTM will recycle the lock function.

Remote Keyless Entry
The [1][2]CTM is compatible with a two button TRW RKE transmitter (keyfob). Two pre-programmed transmitters will be supplied with each vehicle. The CTM is capable of retaining up to four transmitters which can be programmed using the DRB. When a signal encoded with the correct vehicle access code is received and contains a valid message, the CTM will activate the corresponding relay to lock or unlock the doors. When an unlock message is sent, all the doors will unlock, the VTSS will disarm and the illuminated entry will be activated. When a lock message is sent and all the doors are closed, all the doors will lock, the VTSS arming sequence will begin and the illuminated entry will turn OFF.

Horn Chirp
When the doors are locked using the transmitter, a horn chirp will sound to let the customer know the doors were locked. The vehicle will be shipped with this function disabled but may be enabled using the DRB. The duration of the horn chirp can also be changed using the DRB.