The input from your brake switch is sent to the processor in the power module. In turn the power module sends power out threw a high side driver(transistor) to your brake lights. If the switch is unpluged and the lights still light the power module is shorted to voltage or transistor is melted to on mode keeping your lights on. There is also several inputs to your instrument cluster as well from the power module.
First inspect if fuse #24 has power with the key on.
Also check, if brake light is coming on or not, when brake pedal depressed:-----Fuse #24 under the hood. Does it recive power? here is the diagram.
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DIAGNOSIS AND TESTING - FRONT CONTROL MODULE
The front control module is a printed circuit board based module with a on-board micro-processor. The front control module interfaces with other electronic modules in the vehicle via the Programmable Communications Interface (PCI) data bus (J1850). In order to obtain conclusive testing the Programmable Communications Interface (PCI) data bus network and all of the electronic modules that provide inputs to, or receive outputs from the front control module must be checked. All PCI (J1850) communication faults must be resolved prior to further diagnosing any front control module related issues.
The front control module was designed to be diagnosed with an appropriate diagnostic scan tool, such as the DRB III®. The most reliable, efficient, and accurate means to diagnose the front control module requires the use of a DRB III® scan tool and the proper Body Diagnostic Procedures manual.
Before any testing of the front control module is attempted, the battery should be fully charged and all wire harness and ground connections inspected around the affected areas on the vehicle.
INSTALLATIONOPERATION
As messages are sent over the PCI bus circuit, the front control module reads these messages and controls power to some of the vehicles electrical systems by completing the circuit to ground (low side driver) or completing the circuit to 12 volt power (high side driver). The following functions are controlled by the Front Control Module:
- Occupant Restraint Controller Voltage
- Headlamp Power with Voltage Regulation
- Side Airbag Voltage
- Electronic Transaxle (Gasoline engine Vehicles)
- Brake Transmission Shift Interlock Functions (BTSI)
- Front Windshield Wiper "ON" Relay Actuation
- Front Windshield Wiper "HI" & "LO" Relay Actuation
- Front Washer Motor
- Rear Washer Motor
- Front Fog Lamp Relay Actuation
- Front and Rear Blower Motor Relay Actuation
- Accessory Relay Actuation
- Electronic Back Light (EBL) Rear Defogger
- Horn Relay Actuation
- Park Lamp Relay Actuation
- Name Brand Speaker (NBS) Relay Actuation
- Headlamp Washer Relay Actuation
- Diesel Cabin Heater (Diesel Engine Vehicles)
The following inputs are Received/Monitored by the Front Control Module:
- B+ Connection Detection
- Ambient Temperature Sensing
- Right/Left Park Lamp Outage
- Ignition Switch Start Only
- Ignition Switch Run and Start Only
- Washer Fluid Level
- Windshield Wiper Park
- Brake Fluid Level
- Back-Up switch
- Stop Lamp Sense
- Engine Crank Signal (Diesel Engine Vehicles)
- Horn Input
- Install the front control module in the intelligent power module assembly by pushing the 49-way electrical connector straight in(front controlmodule).
- Install the front control module retaining screws. Torque the screws to 7 in. lbs.
- Rotate the intelligent power module assembly downward to secure in mounting bracket.
- Install the battery in the vehicle. Refer to the procedure in Battery Systems.
- Connect the positive and negative battery cables.
NOTE: If the vehicle is not equipped with Name Brand Speakers (Infinity, etc.) or Headlamp Washers the DRB III® must be used to Disable the appropriate relays in the Intelligent Power Module Assembly.
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DESCRIPTION
The Intelligent Power Module (IPM) is a combination of the Power Distribution Center (PDC) and the Front Control Module (FCM). The IPM is located in the engine compartment, next to the battery on this model(Battery terminal guard). The power distribution center mates directly with the Front Control Module (FCM) to form the Intelligent Power Module Fuse and Relay center. The power distribution center (PDC) is a printed circuit board based module that contains fuses and relays, while the front control module contains the electronics controlling the intelligent power module and other functions. This intelligent power module connects directly to the battery positive via a four pin connector. The ground connection is via two other connectors. The intelligent power module provides the primary means of voltage distribution and protection for the entire vehicle.
The molded plastic intelligent power module housing includes a base and cover. The intelligent power module cover is easily opened or removed for service access by squeezing the two marked cover latches and has a fuse and relay layout map integral to the inside surface of the cover. This intelligent power module housing base and cover are secured in place by an intelligent power module mounting bracket. This mounting bracket is designed to allow the intelligent power module to rotate counter-clockwise once the locking tab is disengaged. The intelligent power module mounting bracket is secured in place by bolts threaded into the left front wheel house.
Replaceable components of the intelligent power module assembly are broken down into the following components: the Power Distribution Center (PDC) (without fuses or relays), the intelligent power module cover, the Front Control Module (FCM), the intelligent power module mounting bracket, intelligent power module bracket retaining clips and the Intelligent Power Module Assembly which includes the power distribution center, the cover and FCM.
------------flip over the power module and under fuse #24 with key on does 12v come from both sides.
Next this wire at the pin shown and color pin 17 white and tan strip wire.
does it have 12v with key on?
INSTRUMENT CLUSTER - BLACK 13 WAY
| CAV | CIRCUIT | FUNCTION |
| 1 | E13 20OR/YL | PANEL LAMPS DRIVER (INSTRUMENT CLUSTER) |
| 2 | L160 20WT/TN (LOWLINE) | RIGHT TURN INDICATOR DRIVER |
| 3 | G7 20VT/GY (HIGHLINE - AUTOMATIC TEMPERATURE CONTROL) | LOW OIL PRESSURE SWITCH SENSE |
| 4 | G3 20VT/LB (HIGHLINE - AUTOMATIC TEMPERATURE CONTROL) | MALFUNCTION INDICATOR LAMP DRIVER |
| 5 | L134 20WT/GY (HIGHLINE - AUTOMATIC TEMPERATURE CONTROL) | HIGH BEAM INDICATOR DRIVER |
| 6 | A701 16BR/RD | FUSED B(+) (HAZARD) |
| 7 | Z108 18BK/LG | GROUND |
| 8 | L161 20WT/LG (LOWLINE) | LEFT TURN INDICATOR DRIVER |
| 9 | D25 20WT/VT | PCI BUS (CLUSTER) |
| 10 | B25 18DG/WT | PARK BRAKE SWITCH SENSE |
| 11 | G26 20VT/OR | CHIME DRIVER |
| 12 | G150 20VT/BR | INSTRUMENT CLUSTER WAKE UP SENSE |
| 13 | Z18 18BK/LB | GROUND |
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Here is a diagram of the pin that receives power to the cluster for back lighting.
jp
On my 2005 Town and Country my instrument panel gauges do not work. All back lights work but not the mileage or gear indicators. All other electronics work. Vehicle starts with and without instrument cluster installed. I have also replaced the cluster and the replacement has the same issues. Is there a particular wire I should test. I have power at pins 1,6 and ground continuity at pin 13. door chime does not work either.
ReplyDeleteI did the brake light test. Found the center upper bulb to be out. Replaced and tested, all brake lights work properly. Checked fuse and found it to be fine, removed fused and tested brake lights and they did not work with fuse removed. reinstalled and brake lights worked properly.
ReplyDelete