When I open the door on my 2005 Caravan, without the key in the ignition, the chime goes on and the open door indicator is lit. Also noticed that the mileage indicator is lit. This just happened. Normally without the key in the ignition and door open, the chime does not go on and the mileage indicator is not lit.

Wiring, schematic, electrical diagrams, torq settings, parts info, error/fault codes, full assembly/dissembly, service instructions and a lot moreetc are basic contents of these online books they here on this website https://big-manuals.com/products/dodge-caravan-2001-2007-workshop-service-repair-manual

Your best bet , take it to a qualified repair shop .
SMART ENTRANCE CONTROL UNIT PFP:28596 Description EKS003A2 OUTLINE The smart entrance control unit totally controls the following body electrical system operations. ? Warning chime ? Rear window defogger and door mirror defogger ? Power door locks ? Remote keyless entry system ? Vehicle security system ? Interior lamp ? Battery saver control BATTERY SAVER CONTROL Interior Lamp/Map Lamp/Vanity Lamps The lamps turn off automatically when the interior lamp, map lamp or/and vanity lamps are illuminated with the ignition key in the OFF position, if the lamp remains lit by the door switch open signal or if the lamp switch is in the ON position for approximately 10 minutes. After lamps are turned off by the battery saver system, the lamps illuminate again when: ? Driver's door is locked or unlocked, ? Door is opened or closed, ? Key is inserted into or removed from the ignition key cylinder. Rear Window Defogger/Door Mirror Defogger Rear window defogger and door mirror defogger are turned off approximately 15 minutes after the rear window defogger switch is turned on. INPUT/OUTPUT

Warning chime Key switch (Insert) Ignition switch (ON) Lighting switch (1st or 2nd) Seat belt buckle switch LH Front door switch LH Warning chime (located in smart entrance control unit)

Nothing for you to remove ! Without a factory scan tool U can do nothing .
TIME CONTROL UNIT PFP:28491 Description (Without Power Door Locks) EKS003A6 OUTLINE The time control unit totally controls the following body electrical system operations. ? Warning chime ? Rear window defogger INPUT/OUTPUT System Input Output Warning chime Key switch (Insert) Ignition switch (ON) Lighting switch (1st or 2nd) Seat belt buckle switch LH Front door switch LH Warning chime (located in time control unit) Rear window defogger Ignition switch (ON) Rear window defogger switch Rear window defogger relay

SMART ENTRANCE CONTROL UNIT PFP:28596 Description EKS003A2 OUTLINE The smart entrance control unit totally controls the following body electrical system operations. ? Warning chime ? Rear window defogger and door mirror defogger ? Power door locks ? Remote keyless entry system ? Vehicle security system ? Interior lamp ? Battery saver control BATTERY SAVER CONTROL Interior Lamp/Map Lamp/Vanity Lamps The lamps turn off automatically when the interior lamp, map lamp or/and vanity lamps are illuminated with the ignition key in the OFF position, if the lamp remains lit by the door switch open signal or if the lamp switch is in the ON position for approximately 10 minutes. After lamps are turned off by the battery saver system, the lamps illuminate again when: ? Driver's door is locked or unlocked, ? Door is opened or closed, ? Key is inserted into or removed from the ignition key cylinder. Rear Window Defogger/Door Mirror Defogger Rear window defogger and door mirror defogger are turned off approximately 15 minutes after the rear window defogger switch is turned on.

Warning chime Key switch (Insert) Ignition switch (ON) Lighting switch (1st or 2nd) Seat belt buckle switch LH Front door switch LH Warning chime (located in smart entrance control unit)

Does it have power locks ?

TIME CONTROL UNIT PFP:28491 Description (Without Power Door Locks) EKS003A6 OUTLINE The time control unit totally controls the following body electrical system operations. ? Warning chime ? Rear window defogger INPUT/OUTPUT System Input Output Warning chime Key switch (Insert) Ignition switch (ON) Lighting switch (1st or 2nd) Seat belt buckle switch LH Front door switch LH Warning chime (located in time control unit) Rear window defogger Ignition switch (ON) Rear window defogger switch Rear window defogger relay

What is it chiming ? Chimes for different reasons , headlamps on , seat belt not buckled , etc.... What warning light is lit on the instrument cluster ? if any . seat belt , air bag's etc...

Audible Warnings Description and Operation
The audible warnings alert the driver of a system concern or a critical vehicle condition. The following lists the audible warning priority and the pulse rate:
Fast rate chime (200 pulses per minute)
Medium rate chime (150 pulses per minute)
Slow rate chime (50 pulses per minute)
Single chime
Fasten Safety Belt Warning
The inflatable restraint sensing and diagnostic module (SDM) activates the fasten safety belt audible warning for 5-8 seconds. The fasten safety belt warning sounds and the fasten seat belt indicator illuminates when the following occurs:
• The ignition switch is in RUN, BULB TEST, or START position.
• The SDM detects that the driver's seat belt is not buckled (signal is low).
If the seat belt is buckled before the ignition is in RUN, BULB TEST, or START position, the chime does not sound. If the seat belt is buckled while the chime is sounding, the chime stops.
Key-In-Ignition Warning
The instrument panel cluster (IPC) activates the key-in-ignition audible warning. The key-in-ignition warning sounds when the following occurs:
• The ignition switch is in OFF, LOCK, or ACCY position.
• The body control module (BCM) determines that the driver's door is open (signal is low).
• The BCM determines that the key-in-ignition switch is closed (signal is low).
Lights On Warning
The instrument panel cluster (IPC) activates the lights on audible warning. The lights on warning sounds when the following occurs:
• The key is not in the ignition.
• The body control module (BCM) determines that the drivers door is open (signal is low).
• The BCM determines that the headlamp switch is in the park or head position.
Rear Parking Assist
The rear object sensor control module activates the audible warning. The audible warning sounds whenever any of the indicators are illuminated on the rear parking assist display. For a description of the rear parking assist system refer to Object Detection Description and Operation.
Turn Signal Reminder
The instrument panel cluster (IPC) sounds the turn signal reminder once per each flash of the turn signal lamps when:
• The ignition switch is in the RUN position.
• The turn signal switch is in either turn position, sensing, within 1 second, an open to B+ transition in the turn signal control circuit (left or right turn).
• The vehicle has traveled a distance of 1.2 km (0.75 mi) by counting pulses on the vehicle speed input circuit.
The IPC turns off the turn signal reminder when either the ignition switch is turned to the LOCK position or to the OFF position, or the turn signal switch returns to the OFF position, sensing, within 1 second, no transitions from open to B+ in either of the turn signal control circuits (left turn or right turn).
Additional Chimes
The following chimes will turn on when an associated indicator turns on in the instrument panel cluster (IPC):
• Low Fuel Indicator
• Low Oil Pressure Indicator
• OVER SPEED indicator
For a description of an indicator refer to Indicator/Warning Message Description and Operation.
For diagnosis of an indicator refer to Symptoms - Instrument Panel, Gages and Console.

Your have a problem with one of these systems , your best bet , take it to a qualified repair shop. They would do diagnostic's to find the problem .

Do any indicators illuminate when the chime sounds?
Go to Symptoms - Instrument Panel, Gages and Console
Go to Step 3
3
Turn the ignition OFF.
Remove the key from the ignition.
Turn the headlamp switch to OFF.
Close all of the vehicle doors.
Open one or more of the vehicle doors
Does the chime sound at all times regardless if the doors are open or closed?
Go to Step 15
Go to Step 4
4
Close all of the vehicle doors.
With a scan tool, observe the LF Door Ajar Switch parameter and the RF Door Ajar Switch parameter in the instrument panel cluster BCM/Inputs data list.
Do all of the Door Ajar Switch parameters display Door Closed?

With a scan tool, observe the Left Rear Door Ajar Sw. parameter and the Right Rear Door Sw. parameter in the instrument panel cluster BCM/Inputs data list.
Do all of the Rear Door Switch parameters display Closed?

This is a 21 step diagnostic trouble shooting flow chart .

NOTE: The generic electronic module/central timer module (GEM/CTM) is connected to the ISO link and is diagnosed through the data link connector (DLC) with a scan tool.
There are five warning chimes and lamps the GEM/CTM controls: headlamps operating without the ignition on (chime only), door ajar (chime and lamp), key-in-ignition (chime only), driver seat belt warning (chime and lamp), and message center.


Audible Warnings Warning Condition Lamp Duration Audible Duration Audible Output Safety Belt 60 Seconds 6 Seconds Chime, 60/Min. 740 Hz Key In Ignition - Continuous Chime, 120/Min. 740 Hz Headlamps On - Continuous Chime, 240/Min. 740 Hz Door Ajar Continuous 1 Second Single Tone, 1000 Hz Message Center (Tone Request) - 1 Second Single Tone, 1000 Hz
When the is turned to RUN or START from OFF or ACC, the chime will sound for six seconds or until the safety belt is buckled.
The will turn on for 60 seconds or until the driver safety belt is fastened. Both the chime and the lamp turn on at the same time.
If the safety belt is buckled before the ignition switch is turned to RUN or START, from OFF or ACC, neither the chime nor lamp will be activated.
Anytime the is changed to RUN from START while the safety belt warning indicator is activated, the safety belt warning indicator will remain activated until either the timing sequence has been executed or the safety belt is buckled.
When at least one door is ajar and the key is in the RUN position, the door ajar cluster lamp is activated and remains on until all doors are closed. A warning tone will sound once any time the key is in the ignition switch and any door is open.
The key-in-ignition warning will sound when the driver side is opened with the key in the and the in OFF or ACC. It will continue to sound until the key is removed, the is closed, or the is in RUN or START.
The headlamp-on reminder chime will be activated if the headlamps or parking lamps are on, the key is not in the ignition switch, and the driver door is opened.
A single tone will be provided each time a ground signal is received from the message center. A one-second tone will sound for warning indications from the message center. A 100 milli-second tone will sound for each message center button depressed.

The audible warnings alert the driver of a system concern or a critical vehicle condition. The radio generates the audible warnings through the left front speaker. The radio receives audible warning requests via the class 2 serial data line from the IPC or body control module (BCM). If the radio receives multiple audible warning requests, the warning with the highest priority sounds first. The following lists the audible warning priority and the pulse rate:
Fast rate chime--200 pulses per minute
Medium rate chime--150 pulses per minute
Slow rate chime--50 pulses per minute
Single chime

Is the sound heard different from typical Audible Warnings ?

Fasten Safety Belt Warning
The radio activates the fasten safety belt audible warning as requested by the IPC. The IPC sends a class 2 message to the radio indicating the chime frequency, slow rate and duration (5 pulses). The fasten safety belt warning sounds and the fasten safety belt indicator illuminates when the following occurs:
• The ignition switch transitions to ON.
• The inflatable restraint sensing and diagnostic module (SDM) detects that the driver's seat belt is not buckled, signal is low. The IPC receives a class 2 message from the SDM indicating the driver's seat belt status.
If the seat belt is buckled when the ignition is turned on, the chime does not sound. If the seat belt is buckled while the chime is sounding, the chime stops. If the seat belt is unbuckled after the initial transition to ON, the chime does not sound.
Headlamps On Warning
The radio activates the headlamps on warning as requested by the body control module (BCM). The BCM sends a class 2 message to the radio indicating the chime frequency, fast rate and duration, continuous. The headlamps on warning sounds when the following occurs:
• The ignition is OFF.
• The BCM determines that the driver's door is open, signal is low.
• The BCM determines that the headlamp switch is in the park or head position.
Key-In-Ignition Warning
The radio activates the key-in-ignition audible warning as requested by the BCM. The BCM sends a class 2 message to the radio indicating the chime frequency, medium rate and duration, continuous. The key-in-ignition warning sounds when the following occurs:
• The ignition switch is OFF.
• The body control module (BCM) determines that the driver's door is open, signal is low.
• The BCM determines that the key-in-ignition switch is closed, signal is low.
Turn Signal Reminder
The radio activates the turn signal warning as requested by the IPC. The IPC sends a class 2 message to the radio indicating the chime frequency, medium rate and duration, continuous. The turn signal warning sounds when the following occurs:
• The ignition switch is in the RUN position.
• The turn signal switch is in either turn position, sensing, within 1 second, an open to B+ transition in the turn signal control circuit, left or right turn.
• The vehicle has traveled a distance of 1.2 km (¾ mi) by counting pulses on the vehicle speed input circuit.
The IPC turns OFF the turn signal reminder when either the ignition switch is turned to the OFF position, or the turn signal switch returns to the OFF position, sensing, within 1 second, no transitions from open to B+ in either of the turn signal control circuits, left turn or right turn.
Additional Chimes
The following chimes will turn ON when an associated indicator/message turns ON in the IPC/DIC:
• ABS indicator
• AWD Disable indicator
• Battery/Charge indicator
• Brake indicator
• Change Engine Oil indicator
• Door Ajar indicator
• Hot Coolant Temp indicator
• Low Brake Fluid indicator
• Low Fuel indicator
• Low Oil Level indicator
• Low Oil Pressure indicator
• Low Tire Pressure indicator/reset
• Low Washer Fluid indicator
• MIL (Service Engine Soon) indicator
• Oil Life Reset
• Park Lamp Out indicator
• Rear Hatch Ajar indicator
• Service Traction System indicator
• Service Vehicle Soon indicator
• TRAC OFF indicator
For a description of an indicator refer to Indicator/Warning Message Description and Operation .
For diagnosis of an indicator refer to Symptoms - Instrument Panel, Gages and Console .

Did the Mechanic check for DTC'S - diagnostic trouble codes in the BCM or insturment cluster ? Did you try a Buick dealer ?

Sometimes the ignition key does not "deactivate" when removing the key...try wiggling the washer behind where the key goes...sometimes this sticks...:)

Get in van. Close doors. Cycle ignition 4 times with key. Do not start. Within 10 seconds of the 4th cycle, press the lock switch on driver door panel. If you here a chime locks are reprogramed.

Section 13-09: Gauges, Warning Devices — Chime System 1996 Windstar Workshop Manual
DESCRIPTION AND OPERATION Warning Chime Systems Three distinct sounds are used to indicate the area of concern. Seat belt warning generates 1 chime per second
key-in-ignition generates 2 chimes per second
headlight on generates 4 chimes per second.
Key-In-Ignition Warning The key-in-ignition warning will sound when the driver's front door (20125) is opened with the key in the ignition switch. It will continue to sound until the key is removed, the front door is closed, the ignition switch is turned to START or the vehicle speed is over 24 kmh (15 mph).

Safety Belt Warning When the ignition switch is turned to RUN or START from OFF or ACC, the chime will sound for six seconds or until the safety belt is buckled.

• The safety belt warning indicator lamp (10C859) will activate for 60 seconds or until the driver's safety belt is fastened. Both the chime and lamp activate at the same time.

Anytime the ignition switch is released from START and returns to RUN while the safety belt lamp or chime is activated, the safety belt warning lamp or chime will remain activated until either the timing sequence has been executed, or the safety belt is buckled.

Headlamp Switch On Warning The chime will be activated if the headlamps or parking lamps are ON, the key is not in the ignition and the driver's door is opened. The chime will sound at a rate of four per second.

Warning Chime Systems The generic electronic module (GEM) will sound the following warnings:

• key-in-ignition warning
• safety belt warning
• headlamp switch ON warning
• door ajar warning

------------------------------------------------------------------------------------------------
Headlamp Switch On Warning The generic electronic module (GEM) sounds when the driver door is opened while the headlamp switch (11654) is in the PARK or HEAD position, and continues to sound at a rate of 4 chimes per second until the headlamp switch is turned off or the driver door is closed.

• When the headlamp switch is in the PARK or HEAD position, power is supplied through Circuit 293 (O/R) to the GEM.
• When the driver door is open, the driver door open warning lamp switch (10B997)is closed and ground is supplied to the generic electronic module (GEM).

A delayed headlamps on repetitive chime will sound for a period of three seconds beginning twenty seconds after the key is turned to OFF, LOCK or ACC, the headlamp switch is in the PARK or HEAD position, and the driver door is closed. Delayed headlamps on is terminated by opening and closing the driver door again.
---------------------------------------------------------------------------------------
Door/Liftgate Ajar Warning The door/liftgate ajar warning functions as follows:

• The generic electronic module (GEM) sounds a warning tone for one second when any vehicle door, liftgate window or the liftgate is ajar without any other door already open and the ignition switch is in the RUN position.
• Power is then supplied through Circuit 627 (BK/O) to the door ajar warning indicator lamp which remains illuminated until all doors are closed or the ignition switch is no longer in the RUN position.

----------------------------------------------------------------------------------------------
Key-in-Ignition Warning The generic electronic module (GEM) sounds when the LH front door is opened with the key in the ignition switch and continues to sound until the key is removed or the door is closed.

• When the key is in the ignition switch, the ignition key warning switch terminal and wire (11A128) is closed and ground is supplied through Circuit 158 (BK/PK) to the generic electronic module (GEM).
• When the LH front door is open, the LH front door open warning lamp switch (10B997) closes and ground is supplied through Circuit 57 (BK) to the generic electronic module (GEM).

-------------------------------------------------------------------------------------
Safety Belt Warning When the ignition switch is turned to RUN or START from the OFF or ACC position and remains in RUN or START, the chime will sound for six seconds or until the safety belt is buckled. The safety belt warning indicator lamp (10C859) will turn on for 60 seconds, or until the LH front safety belt is fastened. Both the chime and lamp activate at the same time. If the safety belt is buckled when the ignition key is turned to RUN or START from OFF or ACC, the lamp will prove out for two seconds, but chime will not be activated. Any time the key is changed to RUN from START while the safety belt warning indicator is activated, the safety belt warning indicator will remain activated until either the timing sequence has been executed, or the safety belt is buckled.