Hello Theengine
and transmission in this cars drive train are fully
electronically controlled by a computer called the PCM (Power Train
Control Module). Whenever a problem like this occurs the computer
stores a record of the problem (there are of course some exceptions
to this, like the fuel pump for instance) in the form of a fault code
in its memory, to read these fault codes you must have the systems
memory scanned with a special tool. Once the fault code(s) are read
you then must perform the appropriate diagnostic testing to find and
resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL THE
DIAGNOSIS & TESTING IS COMPLETED.
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Take it to a qualified repair shop, unless you know about C.A.N - controller area network - serial data communication network between modules . U1900 -20 - ic states that one of the 8 or 10 or more modules on your vehicle has stopped talking .
U1900
CAN Communication Bus Fault-Receive Error
RCM
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
Occupant Classification Sensor
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
SJB
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
DVD Player
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
Audio Control Module (with Navigation)
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
Audio Control Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
SDARS
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
Retractable Running Board Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
ABS Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
Parking Aid Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
4WD Control Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
Instrument Cluster
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication BUS Fault - Receiver Error
DSM
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
apers ???? What's this ?
U1900
CAN Communication BUS Fault-Receive Error
ABS Module
REFER to Section 418-00 .
U1900
CAN Communication BUS Fault-Receive Error
Instrument Cluster
REFER to Section 418-00 .
U1900
CAN Communication BUS Fault-Receive Error
Trailer Brake Controller
REFER to Section 418-00 .
Your best bet, take it to a qualified repair shop.
U1900
CAN Communication Bus Fault - Receive Error
ABS Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
Instrument Cluster
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
TBC Module
REFER to Section 418-00 .
Your best bet , have a qualified technician diagnose it .
Communications Network
Vehicle communication utilizes a high speed controller area network (HS-CAN), International Standards Organization (ISO) 9141 network and universal asynchronous receiver-transmitter (UART)-based protocol (UBP) network. Information is sent to and from individual control modules that each control specific functions. All 3 networks are connected to the data link connector (DLC). The DLC can be found under the instrument panel between the steering column and the audio unit.
The 3 module communication networks are:
High speed (HS) CAN
ISO 9141
UBP
ISO 9141 is for diagnostic use only while UBP and CAN allow multiple modules to communicate, or transfer data, with each other on a common network.
Module Name
Network Type
Termination Module
Anti-lock brake system (ABS) module
HS-CAN
No
Electronic automatic temperature control (EATC) module (if equipped)
UBP
N/A
Instrument cluster (gateway module)
HS-CAN and UBP
Yes
Parking aid module (PAM) (if equipped)
ISO 9141
N/A
Powertrain control module (PCM)
HS-CAN
Yes
Restraints control module (RCM)
ISO 9141
N/A
Trailer brake control (TBC) module (if equipped)
HS-CAN
No
Vehicle security module (VSM) (if equipped)
UBP
N/A
Four wheel drive (4WD) control module (if equipped)
ISO 9141
N/A
ISO 9141 Network Operation
The ISO 9141 communication network is a single wire network, used for diagnostic purposes only.
The ISO 9141 communication network is used for the following modules:
Parking aid module
RCM
4WD control module
UART-Based Protocol (UBP) Communication Network
The UBP communication network is a single wire network. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The UBP communication network is used for the following modules:
EATC
Instrument cluster
Vehicle security module
HS-CAN Network Operation
The HS-CAN network uses an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The HS-CAN is a high speed communication network used for the following modules:
ABS module
Instrument cluster
PCM
Trailer brake control module
Network Termination
The CAN network uses a network termination circuit to improve communication reliability. The network termination of the CAN bus takes place inside the termination modules by termination resistors. Termination modules are located at either end of the bus network. As network messages are broadcast, in the form of voltage signals, the network voltage signals are stabilized by the termination resistors. Each termination module has a 120 ohm resistor across the positive and negative bus connection in the termination module. With two termination modules on each network, and the 120 ohm resistors located in a parallel circuit configuration, the total network impedance, or total resistance is 60 ohms.
Network termination improves bus message reliability by:
stabilizing bus voltage.
eliminating electrical interference.
Gateway Module
The instrument cluster is the gateway module, translating HS-CAN to MS-CAN and vice versa. This information allows a message to be distributed throughout both networks. The instrument cluster is the only module on this vehicle that has this ability.
All you need to do is find out which module isn't communicating
Communication Network Diagnostic Trouble Codes (DTC) Index NOTE: DTC U1900 will set in a module that is reporting a communication fault from another module on the data bus. The module that reports the fault is not the problem module.
DTC
Description
Source
Action
U0073
Control Module Communication Buss Off
ABS module
DTC U0073 indicates the module could not communicate on the network at a point in time. The fault is not currently present. CLEAR the DTC. REPEAT the network test with scan tool.
U0073
Control Module Communication Buss Off
Instrument cluster
DTC U0073 indicates the module could not communicate on the network at a point in time. The fault is not currently present. CLEAR the DTC. REPEAT the network test with can tool.
U1900
CAN Communication Bus Fault-Recieve Error
ABS module
For module that failed network test, GO to Symptom Chart .
U1900
CAN Communication Bus Fault-Recieve Error
Instrument cluster
For module that failed network test, GO to Symptom Chart .
U1900
CAN Communication Bus Fault-Receive Error
TBC module
For module that failed network test, GO to Symptom Chart .
U1950
UBP Communication Bus Fault
Vehicle security module
For module that failed network test, GO to Symptom Chart .
U2023
Fault Received From External Node
Instrument cluster
RETRIEVE and FOLLOW non-network DTCs from other modules. REFER to Section 419-10 .
U2226
UBP Invalid Data From Node ID $10 (PCM)
Vehicle security module
RETRIEVE and FOLLOW non-network DTCs from the PCM. REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
All other DTCs
-
-
REFER to Section 419-10 .
Read more: https://www.autocodes.com/u1900_ford.html
Possible causes
Faulty / intermittent ignition switch connections
CAN Bus wiring intermittently open/shorted to power or ground Faulty / intermittent connection at PCM
Faulty electrical connections at ABS Control Module
Faulty electrical connections at the instrument cluster
Poor connections at the trailer brake controller/trailer connector
Tech notes This is typically a false/intermittent code. It can occur if: Someone hooks up a scanner to the OBDII port while the ignition is on or while the engine is idling. A trailer brake system is installed improperly/incorrectly on a truck with ABS (anti-lock brakes).
When is the code detected? When the PCM, Brake Controller and Instrument Cluster are unable to communicate with each other at any time while the ignition switch is turned to the "Run" position, code U1900 sets in memory.
Possible symptoms Engine Light ON (or Service Engine Soon Warning Light) Amber ABS (Anti-lock Brakes) Light ON Wrench Light On
U1900 Ford Description The Anti-ock Brakes System (ABS) module, the Powertrain Control Module (PCM), and the instrument cluster communicate over the Controller Area Network (CAN) Bus. This is a high-speed bus communication system and is not fault tolerant, which means any type of intermittent/loose connection between these 3 controllers will cause communication to stop. When the PCM, ABS module and instrument cluster are unable to communicate with each other at any time while the ignition switch is turned on, code U1900 will set.
U1900 = CAN COMMUNICATION BUS FAULT - RECEIVE ERROR
P0400 = Exhaust gas recirculation (EGR) system - flow malfunction.
The U1900 code shows a problem with the ECU, (brain), struggling to communicate with the rest of the electronics in the car. You will need a specialist auto electrician to fix this.
The P0400 code shows the Exhaust Gas Recirculation system has a fault. A good mechanic should be able to sort this as it is a gas flow issue.
U1900
CAN Communication Bus Fault
Vehicle Security Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault
4WD Control Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
Parking Aid Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
DSM
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
Instrument Cluster
If the 4X4 light is not flashing at key ON, REFER to Section 418-00 .
If the 4X4 light is flashing at key ON, REFER to Section 308-07A .
U1900
CAN Communication Bus Fault-Recieve Error
Power Liftgate Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
Stability Assist Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Recieve Error
Air Suspension Module
REFER to Section 418-00 .
which module won't communicate ? need a up scale scanner to communicate with all the modules on the vehicle. Do you know what C.A.N - controller area network is ? Serial data bus (network) All the modules on the vehicle share data on the network . U code's indicate a problem with the network .
Where did you pull this code from ? What type scan tool did you use ,or was it a code reader ? Do you know about data communication networks on modern cars ? A U codes indicate a communication problem on the data network .
U1900
CAN Communication Bus Fault-Receive Error
Audio Control Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
ABS Module
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
Instrument Cluster
REFER to Section 418-00 .
U1900
CAN Communication Bus Fault-Receive Error
SJB
REFER to Section 418-00 .
The thing that would make this easier to diagnose would be to have a factory scan tool or a professional grade . Need to know what modules can communicate with scan tool .Honestly ,Don't think you can fix this . Dealer or ASE certified repair shop .Do you know what C.A.N. - controller area network is ?
The vehicle has 3 module communications networks:
high speed controller area network (CAN)
medium speed CAN
international standards organization (ISO) 9141 communications network
The diagnostic tool connects to the communications networks through the data link connector (DLC). The DLC allows a diagnostic tool access to diagnose and test the vehicle systems of any module on the communications networks.
All 3 communications networks are connected to the DLC. This makes diagnosis and testing of these systems easier by allowing one diagnostic tool to be able to diagnose and control any module on the 3 communications networks from one common connector. The DLC can be found under the instrument panel between the steering column and the driver door. Which module doesn't communicate with scan tool ?
Symptom Chart
Condition
Possible Sources
Action
The anti-lock brake system (ABS) module does not respond to the diagnostic tool
Circuit or connection in the high speed controller area network (CAN)
ABS module
Go To Pinpoint Test A .
The audio unit does not respond to the diagnostic tool
Circuit or connection in the medium speed controller area network (CAN)
Audio unit
Go To Pinpoint Test B .
Circuit or connection in the medium speed controller area network (CAN)
Audio unit
Go To Pinpoint Test B .
The instrument cluster does not respond to the diagnostic tool - high speed controller area network (CAN)
Circuit or connection in the high speed CAN
Instrument cluster
Go To Pinpoint Test C .
The instrument cluster does not respond to the diagnostic tool - medium speed controller area network (CAN)
Circuit or connection in the medium speed CAN
Instrument cluster
Go To Pinpoint Test D .
The powertrain control module (PCM) does not respond to the diagnostic tool
Circuit or connection in the high speed controller area network (CAN)
PCM
Go To Pinpoint Test E .
The restraint control module (RCM) does not respond to the diagnostic tool
Circuit or connection in the international standards organization (ISO) 9141 communications network
RCM
Go To Pinpoint Test I .
The smart junction box (SJB) does not respond to the diagnostic tool
Circuit or connection in the medium speed controller area network (CAN)
SJB
Go To Pinpoint Test F .
No high speed controller area network (CAN) communication
Circuit or connection in the high speed CAN
High speed CAN modules
Go To Pinpoint Test G .
No medium speed controller area network (CAN) communication
Circuit or connection in the medium speed CAN
Medium speed CAN modules
Go To Pinpoint Test H .
No international standards organization (ISO) 9141 communications network communication
Circuit or connection in the ISO 9141 communications network circuit
Restraint control module (RCM)
Go To Pinpoint Test I .
No module/network communication - no power to the diagnostic tool
Do you know what a serial data network is ? With all the computers car makers put on thier cars these day's they need a communication network for them to talk ,share info. on etc. U codes are codes for the network . A module could be down ,could be a wiring problem . A shorted module or bus wire can bring down the whole vehicle. Could cause the vehicle not to start ,systems not to function . How did you pull this code ,with what scan tool or code reader ? Did it come from the PCM - engine computer ? Need a up scale professional scan tool to check all module's on the vehicle , need to pin point the module that is causing the problem .
U1900
CAN Communication Bus Fault - Receive Error
4WD Control Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
ABS Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
DSM
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
Instrument Cluster
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
Occupant Classification Sensor Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
Parking Aid Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
RCM
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
U1900
CAN Communication Bus Fault - Receive Error
Retractable Running Board Module
REPAIR all other DTCs first. CLEAR the DTCs. CYCLE the key OFF then ON and wait 10 seconds. REPEAT the self-test. If DTC U1900 is still present, REFER to Section 418-00 .
016 CAN Communications
SECTION 418-00: Module Communications Network
2007 Explorer/Mountaineer/Explorer Sport Trac Workshop Manual
DESCRIPTION AND OPERATION
Procedure revision date: 08/02/2006
Communications Network
Vehicle communication utilizes both medium and high speed controller area network (CAN) communications. CAN is used for many modules to communicate with each other on a common network. CAN in-vehicle networking, is a method for transferring data among distributed electronic modules via a serial data bus. Without serial networking, intermodule communication requires dedicated, point to point wiring resulting in bulky, expensive, complex, and difficult to install wiring harnesses. Applying a serial data network reduces the number of wires combining the signals on a single network. Information is sent to the individual control modules that control each function.
The vehicle has 2 module communication networks:
Medium speed (MS) CAN
High speed (HS) CAN
Both networks are connected to the data link connector (DLC). This makes diagnosis and testing of these systems easier by allowing one scan tool to be able to diagnose and control any module on both networks from one connector. The DLC can be found under the instrument panel between the steering column and the audio unit.
Network Topology
Module Name
Network Type
Termination Module
Anti-lock brake system (ABS) module
HS-CAN
No
Audio control module (ACM)
MS-CAN
No
Digital versatile disc (DVD) player (if equipped)
MS-CAN
No
Driver seat module (DSM) (if equipped)
MS-CAN
No
Electronic automatic temperature control (EATC) module (if equipped)
MS-CAN
No
Four wheel drive (4WD) control module (if equipped)
HS-CAN
No
Instrument cluster (IC) (gateway module)
HS-CAN
MS-CAN
Yes
Yes
Occupant classification sensor (OCS) module
HS-CAN
No
Parking aid module (PAM) (if equipped)
MS-CAN
No
Powertrain control module (PCM)
HS-CAN
Yes
Power running board (PRB) module (if equipped)
MS-CAN
No
Restraints control module (RCM)
HS-CAN
No
Satellite digital audio radio system (SDARS) (if equipped)
MS-CAN
No
Smart junction box (SJB)
MS-CAN
Yes
Transmission control module (TCM) (if equipped)
HS-CAN
No
MS-CAN Network Operation
The MS-CAN network communicates using bussed messages. The MS-CAN has an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The MS-CAN is a medium speed communication network used for the following modules:
SJB
Audio unit
Instrument cluster
DSM (if equipped)
DVD player (if equipped)
EATC module (if equipped)
Parking aid module (if equipped)
Satellite audio receiver (if equipped)
Power running board module (if equipped)
HS-CAN Network Operation
The HS-CAN network communicates using bussed messages. The HS-CAN network uses an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The HS-CAN is a high speed communication network used for the following modules:
PCM
TCM (if equipped)
RCM
ABS module
Instrument cluster
Occupant classification sensor module
4WD control module (if equipped)
Network Termination
The CAN network uses a network termination circuit to improve communication reliability. The network termination of the CAN bus takes place inside the termination modules by termination resistors. Termination modules are located at either end of the bus network. As network messages are broadcast in the form of voltage signals, the network voltage signals are stabilized by the termination resistors. Each termination module has a 120 ohm resistor across the positive and negative bus connection in the termination module. With 2 termination modules on each network, and the 120 ohm resistors located in a parallel circuit configuration, the total network impedance, or total resistance is 60 ohms.
Network termination improves bus message reliability by:
stabilizing bus voltage.
eliminating electrical interference.
Gateway Module
The instrument cluster is the gateway module, translating HS-CAN to MS-CAN and vice versa. This information allows a message to be distributed throughout both networks. The instrument cluster is the only module on this vehicle that has this ability.
Hello Theengine
and transmission in this cars drive train are fully
electronically controlled by a computer called the PCM (Power Train
Control Module). Whenever a problem like this occurs the computer
stores a record of the problem (there are of course some exceptions
to this, like the fuel pump for instance) in the form of a fault code
in its memory, to read these fault codes you must have the systems
memory scanned with a special tool. Once the fault code(s) are read
you then must perform the appropriate diagnostic testing to find and
resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL THE
DIAGNOSIS & TESTING IS COMPLETED.
×