I have a rm 3862 dom. refer. and It is no longer working upon visual insp. I found a switch with 22 gauge wire attached to the 12 volt supply bus and it was attached across the pos. and neg. terminal which makes no sense to me and now the relays on the bd are chattering so I assume the board is bad and I plan to replace it but I just don't know what to do about the switch that was very obviously added after

U codes pertain to serial data network . All the control module's on the vehicle share info. , send commands etc... on the data bus . U110C-NO FUEL LEVEL BUS MESSAGE RECEIVED For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The fuel level signal is a direct input to the Cluster. The fuel level signal is sent to the TIPM over the CAN B bus circuit. The NGC receives the fuel level signal from the TIPM over the CAN C bus circuit.

1. When Monitored: Ignition on.
   
2. Set Condition: When the PCM does not receive a fuel level signal from the TIPM over the CAN C circuit. The circuit is constantly monitored.
   

3. Possible Causes

   CAN C BUS CIRCUIT OPEN OR SHORTED TOTALLY INTEGRATED POWER MODULE PCM
4. OPERATION The ElectroMechanical Instrument Cluster (EMIC) in this model also includes the hardware and software necessary to serve as the electronic body control module and is sometimes referred to as the Cab Compartment Node or CCN. The following information deals primarily with the instrument cluster functions of this unit. Additional details of the electronic body control functions of this unit may be found within the service information for the system or component that the CCN controls. For example: Additional details of the audible warning functions of the CCN are found within the Chime/Buzzer service information.
   The CCN is designed to allow the vehicle operator to monitor the conditions of many of the vehicle components and operating systems. The gauges and indicators in the CCN provide valuable information about the various standard and optional powertrains, fuel and emissions systems, cooling systems, lighting systems, safety systems and many other convenience items. The CCN is installed in the instrument panel so that all of these monitors can be easily viewed by the vehicle operator when driving, while still allowing relative ease of access for service.
   The microprocessor-based CCN hardware and software uses various inputs to control the gauges and indicators visible on the face of the cluster. Some of these inputs are hard wired, but most are in the form of electronic messages that are transmitted by other electronic modules over the Controller Area Network (CAN) data bus and the Local Interconnect Network (LIN) data bus. The CCN is the master of the LIN bus and there are five modules that talk to the CCN (Smart Glass Module (SGM) - PT27 only, Heated Seat Module (HSM), Remote Compass Module (RCM), Steering Column Control Module (SCCM), and the Accessory Switch Bank Module (ASBM) (Refer to 08 - Electrical/Electronic Control Modules/COMMUNICATION - Operation).
   The CCN microprocessor smooths the input data using algorithms to provide gauge readings that are accurate, stable and responsive to operating conditions. These algorithms are designed to provide gauge readings during normal operation that are consistent with customer expectations. However, when abnormal conditions exist such as high coolant temperature, the algorithm can drive the gauge pointer to an extreme position and the microprocessor can sound a chime through the on-board audible tone transducer to provide distinct visual and audible indications of a problem to the vehicle operator. The CCN may also produce audible warnings for other electronic modules in the vehicle based upon electronic tone request messages received over the CAN/LIN data bus. Each audible warning is intended to provide the vehicle operator with an audible alert to supplement a visual indication.
   The CCN circuitry operates on battery current received through a fused B(+) fuse on a non-switched fused B(+) circuit, and on battery current received through a fused ignition switch output (run-start) fuse on a fused ignition switch output (run-start) circuit. This arrangement allows the/CCN to provide some features regardless of the ignition switch position, while other features will operate only with the ignition switch in the On or Start positions. The CCN circuitry is grounded through a ground circuit of the instrument panel wire harness.
   The CCN also has a self-diagnostic actuator test capability which will test each of the CAN bus message-controlled functions of the cluster by lighting the appropriate indicators, positioning the gauge needles at several predetermined calibration points across the gauge faces, and illuminating all segments of the odometer/trip odometer/gear selector indicator Vacuum-Fluorescent Display (VFD) unit and Electronic Vehicle Information Center (EVIC). The EVIC will display the hardware/software version, and the CAN and LIN Vehicle Maintenance Monitor (VMM) used in the CCN. (Refer to 08 - Electrical/Instrument Cluster - Diagnosis and Testing).

Fuses? Blown fusible link? Most gauges work by getting 12 volts from the ignition switch when on, and getting a ground from the sender. Often the 12 volt supply wire goes to more than one so if dead, both will fail. If you have a wiring diagram, you might find which wire to cluster should be hot, and trace it backward to find the issue. Easier to check for ignition switch feed first.

Locate converter and check for blown fuse(s) on converter first.

Code 11 means no distributor reference signal detected during cranking. Check the circuit between the Distributor and PCM (computer). Also, keep in mind the following operations/tests apply to these relays only: Automatic Shutdown (ASD) , Fuel Pump and Ballast Bypass. For operations/tests on all other relays refer to the appropriate test.

OPERATION:
The relay terminal numbers can be found on the bottom of the relay.
Terminal number 30 is connected to battery voltage and can be switched or B + (hot) at all times.
Terminal number 87A is connected (a circuit is formed) to terminal 30 in the de-energized (normally OFF) position.
Terminal number 87 is connected (a circuit is formed) to terminal 30 in the energized (ON) position. Terminal number 87 then supplies battery voltage to the component being operated.
Terminal number 86 is connected to a switched power source.
Terminal number 85 is grounded by the Engine Controller.

TESTING:
Remove relay before testing.
Using an ohmmeter, perform a resistance test between terminals 85 and 86. Resistance value (ohms) should be 75 ±5 ohms for resistor equipped relays.
Connect the ohmmeter between terminals number 87A and 30. Continuity should be present at this time.
Connect the ohmmeter between terminals number 87 and 30. Continuity should not be present at this time.
Use a set of jumper wires (16 gauge or smaller). Connect one jumper wire between terminal number 85 (on the relay) to the ground side (-) of a 12 Volt power source.
Attach the other jumper wire to the positive side (+) of a 12V power source. Do not connect the jumper wire to relay at this time.

CAUTION: Do not allow the ohmmeter to contact terminals 85 or 86 during these tests. Damage to ohmmeter may result.

Attach the other jumper wire (12V +) to terminal number 86. This will activate the relay. Continuity should now be present between terminals number 87 and 30. Continuity should not be present between terminals number 87A and 30.
Disconnect jumper wires from relay and 12 Volt power source.

If continuity or resistance tests did not pass replace relay. The Powertrain Control Module (PCM) and connector are located in the engine compartment, mounted to the inner fender, next to the air cleaner housing (click image fo zoom).
DTC 11 - No reference signal during engine cranking. No camshaft reference signal was detected during engine cranking.
DTC 12 - Battery disconnect. Battery input to PCM disconnected during last 50 key starts.
DTC 42 - ASD relay control circuit. An open or shorted condition detected in the auto shut down relay circuit.



Hope helps.

You can jumper on an ATX power supply by using a wire to connect pin 4 (green wire) to any of the grounds on the 20 pin ATX connector. The grounds are normally a black wire. You will need to put some sort of load on the power supply such as a hard drive to keep it running.

Power for the transfer case selector switch comes from the "GAUGES" fuse. It is fuse #4 in the left end instrument panel fuse block. This 12 volt supply goes to the switch via the "PINK" wire in position "C" of the switch connector.

Bad Power Supply.

Weak Voltage power rail. Enough power to light those two LED lights, but not enough power for the Processor.

Be nice if I knew the computer manufacturer name, and the Model Number.

A) When the computer's Power Supply is plugged into power, there is a 5 Volt Standby power present for the Power Supply.

This 5 Volt Standby power is what activates, (Turns on) the Power Supply, when you press the Power On button.
(The Power On switch located within the plastic Power On button, is a Momentary Contact Switch)

Power Supply activates, sends power to the motherboard.
(That LED light on the motherboard, indicates the motherboard is receiving power. Has nothing to do with the CMOS battery located on the motherboard)

The first chip to receive power is the BIOS chip.
(Chip and Chipset are slang terms for I.C.
Integrated Circuit

http://en.wikipedia.org/wiki/Integrated_Circuit )

Power to the BIOS chip initializes the BIOS program, which is burned into the chip.

BIOS (program) looks to see what devices are installed, does a Ram Memory count, TURNS the Processor on, and hands the computer over to the O/S.

(O/S. Operating System. Windows XP is one example of an O/S)

1) ALL the LED lights use less than 1 Watt of power.
To include the Power On LED, the LED on the motherboard, and the LED light on the Power Supply.

2) EACH fan uses 2 to 3 Watts. So if you see any fans spinning, (Then stop of course), they don't use squat for power.

3) A typical Processor uses 51 to 125 Watts. (Less for older Processors such as the Intel Pentium III's, and what have you)

So you are getting power, right up to the point that BIOS goes to turn the Processor on, then there isn't enough power to turn the Processor on, or keep it on.

Bad Power Supply.
Weak Voltage power rail

The SMPS (Switched-Mode Power Supply) in your computer produces three main Voltages.

A) 3.3 Volts (3 point 3)
B) 5 Volts
C) 12 Volts

[All are DC voltage.
Two D cell flashlight batteries produce 3 Volts DC ]

http://en.wikipedia.org/wiki/Switched-mode_power_supply

Wires that have Orange insulation on them are 3.3 Volt wires.
Red wires are 5 Volts
Yellow wires are 12 Volts.

You will see many wires in the cables inside the computer, that carry these colors.

All of these wires terminate inside the power supply.
EACH Voltage terminates in One terminal point within the circuitry of the Power Supply.

The 3.3 Volt wires terminate in one central point, in the circuitry within the Power Supply.
This is the 3.3 Volt power rail.

The 5 Volt wires, and 12 Volt wires follow suit.
There is a 5 Volt power rail, and a 12 Volt power rail.

Hence the term Power Rail, and my reference above to - Weak Voltage power rail.

The power rail to be most concerned with when testing a Power Supply, is the 12 Volt power rail.

You can test it with an economical multimeter, (Translates to cheap), or an economical power supply tester.

Economical multimeter's run from $5 to $12.
Found in a variety of stores. An auto parts store may be one avenue of approach, and perhaps Radio Shack. (Not advertising for Radio Shack)

This is one example of a power supply tester,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250576&CatId=5471

Power Supply unplugged from power, the Positive (Red) probe lead of the multimeter, is connected to any Yellow wire.
I attach an alligator clip to the probe lead, and clip it to a metal terminal at the end of a Yellow wire.

The Negative (Black) probe lead is connected to a Ground wire.
ANY wire that has Black insulation on it, is a Ground wire.

Then plug the Power Supply into power, press the Power On button, observe what Voltage is present.

11 to 13 Volts indicates the Power Supply is fine.\
Less than 11 Volts means it's time to replace the Power Supply.

[NOTE*
Should state.
BEFORE you reach inside your open computer case to test the 12 Volt power rail, the computer should be unplugged from power.
You should also observe Anti-Static precautions.

Anti-Static Precautions:
Your body carries Static electricity.
Static WILL fry out (Short Circuit) the delicate hardware components inside a computer.

You may not even see it, or feel it.

Computer unplugged from power, computer case open, TOUCH the metal frame of the open computer case.
This action will relieve your body of Static.

Should you leave your computer in the middle, while working on it, upon your return Touch the metal frame again.
Or use a $6 ESD wrist strap, and connect the alligator clip to the metal frame.
(Electro Static Discharge)

Or, you can use a KNOWN to be good, Compatible power supply for a test unit.

It has to be KNOWN to be good, or you will be right back to where you are now.

Compatible:
Has to have the correct power cables, and has to have at least the minimum amount, of power cables needed.
Extra power cables can be tied up out of the way. (Use plastic ties, not paper wrapped metal, bread ties)

Reference to power cables, and their respective connectors, used in personal computers,

http://www.playtool.com/pages/psuconnectors/connectors.html

[There are those who may have a computer that is unused, and sitting around.
Has been replaced by a newer computer, or what have you.

The Power Supply could be borrowed for the test, then returned to the donor computer.
IF, the Power Supply is KNOWN to be good, and Compatible.
Just food for thought ]

DO NOT open a Power Supply, and attempt to repair it!

Inside the Power Supply are various hardware components.
Some of these components are Electrolytic Capacitors.

[One's used in Power Supply's at present, {To my knowledge}, are Radial Aluminum Electrolytic Capacitors,

http://en.wikipedia.org/wiki/Electrolytic_capacitor ]

The basic operation of a Capacitor is to slowly build up a charge, then release it all at once.

Think of a large swimming pool being filled up by a garden hose, then when full, one side of the pool is taken down all at once.

IF, your finger/s touch the terminals on the bottom of a charged capacitor, the charge can be released to You!

IF, your finger/s touch a circuit that one, or more capacitors are in, and your fingers complete the circuit, the charge can be released to You!

BAD shock to FATAL!

The capacitors are discharged in a proper manner, with a proper device, before working on an electronic device. (One example is a computer Power Supply)

I found out that the AT supply SA145-3435 does not have a switch wire like an ATX supply. I have a SA145-3435 my self. To get it to work it must have a +5 volt load (BLACK and RED) and a +12 volt load (BLACK and YELLOW). If it does not have both of these loads it will power down after a 2 second delay when you plug it up. I used 2 small 12 volt bulbs. One for the 12 volt line and one for the 5 volt line. The type of blub I used was a #94 I got from the auto parts store.

Hello lybolts3...You will need a digitial multimeter to help troubleshoot this problem. With this you can help determine the problem. No doubt you have more than 5 amps through the circuit, causeing the fuse to blow.Check the actual amperage and voltage at the fuse box, make sure it has a good ground... a bad ground will have the same effect as a short...If you have a good ground, 12 volts and bus voltage on the plus and minus
bus wires the cluster should work. both bus wires should be around 2.5 volts. If one of the bus wires is 2.2v the other should be 2.3v and so on. The back of the instrument cluster where the connectors attach is another place to check...clusters have been known to fail..a bad soder or corroded pin. Last but not least..the ignition switch and the BCM...the gauges get their info from the BCM and the switch powers it.
Good luck..i hope this helps..please rate me a fixya.

I found that they rewired the 12 volt supply, red wire, thru a heat safety switch on the burner unit and it was open instead of being closed and cut off the main 12 volt supply to the control board. I connected a jumper wire around the new switch and the frig works . either the new switch is bad or too close to the heating unit.