Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSDODGE AND RAM2006MAGNUM V6-2.7L VIN TREPAIR AND DIAGNOSISA L L DIAGNOSTIC TROUBLE CODES ( DTC )TESTING AND INSPECTIONU CODE CHARTSU0019BODY CONTROL SYSTEMS
2006 Dodge and Ram Magnum V6-2.7L VIN T
Body Control Systems
2006 Dodge and Ram Magnum V6-2.7L VIN TSECTION Body Control Systems
U0019-CAN B BUS
WHEN MONITORED
With the ignition on.
SET CONDITION
The FCM detects an open, a short high, a short low or a short together in either of the CAN B Bus circuits.
POSSIBLE CAUSES
- (D55) CAN B BUS (+) circuit shorted to ground
- (D54) CAN B BUS (-) circuit shorted to ground
- (D55) CAN B BUS (+) circuit shorted to voltage
- (D54) CAN B BUS (-) circuit shorted to voltage
- (D55) CAN B BUS (+) circuit shorted to (D54) CAN B BUS (-) circuit
- (D55) CAN B BUS (+) circuit open
- (D54) CAN B BUS (-) circuit open
- Any CAN B BUS module
DIAGNOSTIC TEST
1. TEST FOR INTERMITTENT CONDITION
Turn the ignition on.
With the scan tool, record and erase FCM DTC's.
Cycle the ignition from on to off 3 times.
Turn the ignition on.
With the scan tool, read active FCM DTC's.
Q: Does the scan tool display this DTC as active?
YES: Go To 2
NO: The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
2. ANY CAN B BUS MODULE-INTERNAL FAULT
Turn the ignition off.
With the scan tool, monitor the active FCM DTCs.
While monitoring the scan tool, disconnect each CAN B Bus module one at a time.
NOTE:
- When performing the above step, turn the ignition off (wait one minute) before disconnecting any module. When the module is disconnected turn the ignition on.
- This is to determine if the fault is internal within a module.
Check for this DTC to become active after disconnecting each CAN B Bus module the vehicle is equipped with.
NOTE: If the DTC becomes stored when a particular CAN B Bus module is disconnected, that module is causing the DTC to set.
Q: With all the CAN B Bus modules disconnected did the FCM still set this DTC as active?
YES: Go To 3
NO: Replace the module that when disconnected the DTC became stored.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
3. (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the Front Control Module C1 harness connector.
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Turn the ignition on.
Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.
Q: Is the voltage above 10.0 volts?
YES: Repair the (D55) CAN B Bus (+) circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 4
4. (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO VOLTAGE
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.
Q: Is the voltage above 10.0 volts?
YES: Repair the (D54) CAN B Bus (-) circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 5
5. (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Measure the resistance between ground and the (D55) CAN B Bus (+) circuit.
Q: Is the resistance above 1000.0 ohms?
YES: Go To 6
NO: Repair the (D55) CAN B Bus (+) circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
6. (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO GROUND
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Measure the resistance between ground and the (D54) CAN B Bus (-) circuit.
Q: Is the resistance above 1000.0 ohms?
YES: Go To 7
NO: Repair the (D54) CAN B Bus (-) circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
7. (D55) CAN B BUS (+) CIRCUIT SHORTED TO THE (D54) CAN B BUS (-) CIRCUIT
Measure the resistance between the (D55) CAN B Bus (+) circuit and (D54) CAN B Bus (-) circuit.
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Q: Is any resistance present?
YES: Repair the (D55) CAN B Bus (+) circuit for a short to the (D54) CAN B Bus (-) circuit.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 8
8. (D55) CAN B BUS (+) CIRCUIT OPEN
Measure the resistance of the (D55) CAN B Bus (+) circuit between the FCM connector and the Cluster connector.
Q: Is the resistance above 10.0 ohms?
YES: Repair the (D55) CAN B Bus (+) circuit for an open or high resistance.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 9
9. (D54) CAN B BUS (-) CIRCUIT OPEN
Measure the resistance of the (D54) CAN B Bus (-) circuit between the FCM connector and the Cluster connector.
Q: Is the resistance above 10.0 ohms?
YES: Repair the (D54) CAN B Bus (-) circuit for an open or high resistance.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace and program the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
U0019 - Can B Bus:
WHEN MONITORED
With the ignition on.
SET CONDITION
The FCM detects an open, a short high, a short low or a short together in either of the CAN B Bus circuits.
POSSIBLE CAUSES
- (D55) CAN B BUS (+) circuit shorted to ground
- (D54) CAN B BUS (-) circuit shorted to ground
- (D55) CAN B BUS (+) circuit shorted to voltage
- (D54) CAN B BUS (-) circuit shorted to voltage
- (D55) CAN B BUS (+) circuit shorted to (D54) CAN B BUS (-) circuit
- (D55) CAN B BUS (+) circuit open
- (D54) CAN B BUS (-) circuit open
- Any CAN B BUS module
DIAGNOSTIC TEST
1. TEST FOR INTERMITTENT CONDITION
Turn the ignition on.
With the scan tool, record and erase FCM DTC's.
Cycle the ignition from on to off 3 times.
Turn the ignition on.
With the scan tool, read active FCM DTC's.
Q: Does the scan tool display this DTC as active?
YES: Go To 2
NO: The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
2. ANY CAN B BUS MODULE-INTERNAL FAULT
Turn the ignition off.
With the scan tool, monitor the active FCM DTCs.
While monitoring the scan tool, disconnect each CAN B Bus module one at a time.
NOTE:
- When performing the above step, turn the ignition off (wait one minute) before disconnecting any module. When the module is disconnected turn the ignition on.
- This is to determine if the fault is internal within a module.
Check for this DTC to become active after disconnecting each CAN B Bus module the vehicle is equipped with.
NOTE: If the DTC becomes stored when a particular CAN B Bus module is disconnected, that module is causing the DTC to set.
Q: With all the CAN B Bus modules disconnected did the FCM still set this DTC as active?
YES: Go To 3
NO: Replace the module that when disconnected the DTC became stored.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
3. (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the Front Control Module C1 harness connector.
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Turn the ignition on.
Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.
Q: Is the voltage above 10.0 volts?
YES: Repair the (D55) CAN B Bus (+) circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 4
4. (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO VOLTAGE
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.
Q: Is the voltage above 10.0 volts?
YES: Repair the (D54) CAN B Bus (-) circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 5
5. (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Measure the resistance between ground and the (D55) CAN B Bus (+) circuit.
Q: Is the resistance above 1000.0 ohms?
YES: Go To 6
NO: Repair the (D55) CAN B Bus (+) circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
6. (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO GROUND
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Measure the resistance between ground and the (D54) CAN B Bus (-) circuit.
Q: Is the resistance above 1000.0 ohms?
YES: Go To 7
NO: Repair the (D54) CAN B Bus (-) circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
7. (D55) CAN B BUS (+) CIRCUIT SHORTED TO THE (D54) CAN B BUS (-) CIRCUIT
Measure the resistance between the (D55) CAN B Bus (+) circuit and (D54) CAN B Bus (-) circuit.
NOTE: Ensure each CAN B Bus module is disconnected at this time.
Q: Is any resistance present?
YES: Repair the (D55) CAN B Bus (+) circuit for a short to the (D54) CAN B Bus (-) circuit.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 8
8. (D55) CAN B BUS (+) CIRCUIT OPEN
Measure the resistance of the (D55) CAN B Bus (+) circuit between the FCM connector and the Cluster connector.
Q: Is the resistance above 10.0 ohms?
YES: Repair the (D55) CAN B Bus (+) circuit for an open or high resistance.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 9
9. (D54) CAN B BUS (-) CIRCUIT OPEN
Measure the resistance of the (D54) CAN B Bus (-) circuit between the FCM connector and the Cluster connector.
Q: Is the resistance above 10.0 ohms?
YES: Repair the (D54) CAN B Bus (-) circuit for an open or high resistance.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace and program the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.