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Home >> Dodge and Ram >> 2012 >> RAM 3500 Chassis Cab Truck 2WD V8-5.7L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> U Code Charts >> U0001 >> Totally Integrated Power Module (TIPM)

Totally Integrated Power Module (TIPM)






U0001-CAN C BUS

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The primary communication network between electronic control modules on this vehicle is the Controller Area Network (CAN) data bus system. The Controller Area Network (CAN) data bus allows all electronic modules connected to the bus to share information with each other. Regardless of whether a message originates from a module on the higher speed CAN C (500K) Bus or on the lower speed CAN Interior High Speed (IHS) (125K) Bus the message structure and layout is similar, which allows the Totally Integrated Power Module/Central GateWay (TIPM or TIPMCGW) to process and transfer messages between the CAN buses. The TIPM also stores Diagnostic Trouble Codes (DTCs) for certain bus network faults.

All modules transmit and receive messages over one of these buses. Data exchange between the modules is achieved by serial transmission of encoded data messages (a form of transmission in which data bits are sent sequentially, one at a time, over a single line). Each module can both send and receive serial data simultaneously. Each data bit of a CAN Bus message is carried over the bus as a voltage differential between the two bus circuits which, when strung together, form a message. Each module uses arbitration to sort the message priority if two competing messages are attempting to be broadcast at the same time. Corruption of a single bit within a message will corrupt the entire message. Each message contains a Cyclic Redundancy Check (CRC) which specifies the message size exactly. If the message detected conflicts with the CRC the ECU receiving it will determine the message to be an error and consider that communication has not been possible. Diagnosis of this condition using a lab scope may reveal activity that appears to be Bus data messages even if no actual communication is possible. Communication problems that affect the whole bus, as a result of opens and terminal push outs are more likely to occur on data busses that operate at a high speed than a data bus that operates at a lower speed.

When an open circuit or terminal push out occurs one or more modules can become isolated from the remainder of the bus. The isolated module will attempt to communicate, but will not be able to receive messages or determine arbitration from other modules. Each time the isolated module attempts to communicate it alters the bus voltage on the intact bus circuit. Without functioning arbitration the isolated module alters the bus voltage while other bus messages are being sent thereby corrupting the messages on the remainder of the bus.

The CAN bus modules are connected in parallel to the two-wire bus using a twisted pair, where the wires are wrapped around each other to provide shielding from unwanted electromagnetic induction, thus preventing interference with the relatively low voltage signals being carried through them. While the CAN bus is operating (active), one of the bus wires will carry a higher voltage and is referred to as the CAN High or CAN bus (+) wire, while the other bus wire will carry a lower voltage and is referred to as the CAN Low or CAN bus (-) wire.

- When Monitored:
With the ignition on.

- Set Condition:
The Totally Integrated Power Module (TIPM) detects a corrupt CAN C Bus message.





1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, record and erase TIPM DTCs.
3. Cycle the ignition from on to off three times.
4. Turn the ignition on.
5. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.

2. ANTILOCK BRAKE MODULE - INTERNAL SHORT
1. Turn the ignition off.
2. Disconnect the Antilock Brake Module harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 3

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the Antilock Brake Module. .
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

3. OCCUPANT RESTRAINT CONTROLLER MODULE - INTERNAL SHORT

WARNING: Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

1. Disconnect the Occupant Restraint Controller Module harness connectors.
2. Reconnect the 12-volt battery.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 4

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Occupant Restraint Controller Module. Occupant Restraint Controller - Removal.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

4. POWERTRAIN CONTROL MODULE - INTERNAL SHORT
1. Turn the ignition off.
2. Disconnect the PCM C1 or PCM C2 (6.7L) harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 5

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the Powertrain Control Module. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. STEERING ANGLE SENSOR - INTERNAL SHORT
1. Turn the ignition off.
2. Disconnect the Clockspring C3 (SAS) harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 6

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Clockspring and program the SAS. .
- Perform the BODY VERIFICATION TEST. Body Verification Test.

6. WIRELESS IGNITION NODE - INTERNAL SHORT
1. Turn the ignition off.
2. Disconnect the Wireless Ignition Node harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 7

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Wireless Ignition Node. .
- Perform the WIRELESS IGNITION NODE (WIN) VERIFICATION TEST. Wireless Ignition Node (WIN) Verification Test.

7. DRIVETRAIN CONTROL MODULE - INTERNAL SHORT
1. Turn the ignition off.

NOTE: If vehicle is not equipped with this module, answer yes to the question.

2. Disconnect the Drive Train Control Module C1 harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 8

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Drivetrain Control Module. .
- Perform the DTCM VERIFICATION TEST. DTCM Verification Test.

8. FINAL DRIVE CONTROL MODULE (FDCM) - INTERNAL SHORT
1. Turn the ignition off.

NOTE: If vehicle is not equipped with this module, answer yes to the question.

2. Disconnect the FDCM harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 9

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the FDCM. .
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.

9. INTEGRATED TRAILER BRAKE MODULE (ITBM) - INTERNAL SHORT
1. Turn the ignition off.

NOTE: If vehicle is not equipped with this module, answer yes to the question.

2. Disconnect the ITBM harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 10

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the ITBM. .
- Perform the BODY VERIFICATION TEST. Body Verification Test.

10. TIRE PRESSURE MONITORING MODULE - INTERNAL SHORT
1. Turn the ignition off.

NOTE: If vehicle is not equipped with this module, answer yes to the question.

2. Disconnect the Tire Pressure Module harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 11

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Tire Pressure Monitoring Module. .
- Perform the TPM VERIFICATION. TPM Verification.

11. TRANSMISSION CONTROL MODULE (TCM) - INTERNAL SHORT
1. Turn the ignition off.

NOTE: If vehicle is not equipped with this module, answer yes to the question.

2. Disconnect the TCM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, record and erase TIPM DTCs.
5. Cycle the ignition from on to off three times.
6. Turn the ignition on.
7. With the scan tool, read active TIPM DTCs.

Does the scan tool display U0001-CAN C BUS as active?

Yes

- Go To 12

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Transmission Control Module. .
- Perform the TCM VERIFICATION TEST. .

12. (D51) OR (D64) CAN C BUS (-) CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the TIPM C7 and C1 harness connectors.
3. Turn the ignition on.
4. Measure the voltage between the (D51) CAN C Bus (-) circuit and ground at the TIPM C7 harness connector.
5. Measure the voltage between the (D64) CAN C Bus (-) circuit and ground at the TIPM C1 harness connector.

Is there any voltage present?

Yes

- Repair the short to voltage in the (D51) or the (D64) CAN C Bus (-) circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 13

13. (D52) OR (D65) CAN C BUS (+) CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Measure the resistance between ground and the (D52) CAN C Bus (+) circuit.
3. Measure the resistance between ground and the (D65) CAN C Bus (+) circuit.

Is any resistance present?

Yes

- Repair the short to ground in the (D52) or (D65) CAN C Bus (+) circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 14

14. CAN C BUS (+) CIRCUIT SHORTED TO CAN C BUS (-) CIRCUIT




1. Measure the resistance between the (D52) CAN C Bus (+) circuit and the (D51) CAN C Bus (-) circuit.
2. Measure the resistance between the (D65) CAN C Bus (+) circuit and the (D64) CAN C Bus (-) circuit.

Is any resistance present?

Yes

- Repair the short between the CAN C Bus (+) circuit and the CAN C Bus (-) circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace the Totally Integrated Power Module. .
- Perform the BODY VERIFICATION TEST. Body Verification Test.

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