U1004

U1004 - CAN C Bus Transmit Performance






For a complete wiring diagram, refer to.

• When Monitored: With the ignition ON.

• Set Condition: When the anti lock brake module detects invalid CAN message from the dynamics sensor.






Test Step 1 - Test for A DTC U1004-CAN C Bus Transmit Performance

• This DTC must be active for the results of this test to be valid.

• Turn the ignition ON.

• With the scan tool, read and record DTCs.

• With the scan tool, read and record Freeze Frame information.

• With the scan tool, erase DTCs.

• Cycle the ignition switch from OFF to ON.

• With the scan tool, read and record DTCs

Does the scan tool display U1004 - CAN C Bus Transmit Performance?

Yes

• Go to Test Step 2 => [ Test Step 2 - Test the Wiring Harness, Terminals, and Connectors ]

No

• Preform the ABS Intermittent Condition Test. Refer to => Non-DTC Based Diagnostics.

Test Step 2 - Test the Wiring Harness, Terminals, and Connectors

• Test the dynamic sensor installation and torque of the mounting bolts.

• Visually inspect the related wiring harness. Look for any bruised, chafed, pierced, or partially broken wires.

• Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Were any problems found?

Yes

• Repair as necessary.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Go to Test Step 3 => [ Test Step 3 - Test the Dynamics Sensor High Data Link Circuit for
a Short to Voltage ]

Test Step 3 - Test the Dynamics Sensor High Data Link Circuit for a Short to Voltage






• Turn the ignition OFF.

• Disconnect the dynamics sensor harness connector.

• Disconnect the anti lock brake module harness connector.

• Turn the ignition ON.

• Measure the voltage of the dynamics sensor high data link circuit.

Is there any voltage present?

Yes

• Repair the dynamics sensor high data link circuit for a short to voltage.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Go to Test Step 4 => [ Test Step 4 - Dynamics Sensor High Data Link Circuit Short to Ground ]

Test Step 4 - Dynamics Sensor High Data Link Circuit Short to Ground






• Turn the ignition OFF.

• Measure the resistance between ground and the dynamics sensor high data link circuit.

Is the resistance less than 5.0 ohms?

Yes

• Repair the dynamics sensor high data Link circuit for a short to ground.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Go to Test Step 5 => [ Test Step 5 - Test the Dynamics Sensor High Data Link Circuit for
An Open ]

Test Step 5 - Test the Dynamics Sensor High Data Link Circuit for An Open






• Measure the resistance of the dynamics sensor high data link circuit.

Is the resistance less than 5.0 ohms?

Yes

• Go to Test Step 6 => [ Test Step 6 - Test the Dynamics Sensor LOW Data Link Circuit for
a Short to Voltage ]

No

• Repair the dynamics sensor high data Link circuit for an open.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

Test Step 6 - Test the Dynamics Sensor LOW Data Link Circuit for a Short to Voltage






• Turn the ignition ON.

• Measure the voltage of the dynamics sensor LOW data link circuit.

Is there any voltage present?

Yes

• Repair the dynamics sensor LOW data link circuit for a short to voltage.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Go to Test Step 7 => [ Test Step 7 - Test the Dynamics Sensor LOW Data Link Circuit for
a Short to Ground ]

Test Step 7 - Test the Dynamics Sensor LOW Data Link Circuit for a Short to Ground






• Turn the ignition OFF.

• Measure the resistance between ground and the dynamics sensor LOW data link circuit.

Is the resistance less than 5.0 ohms?

Yes

• Repair the dynamics sensor LOW data link circuit for a short to ground.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Go to Test Step 8 => [ Test Step 8 - Test the Dynamics Sensor LOW Data Link Circuit for
an Open ]

Test Step 8 - Test the Dynamics Sensor LOW Data Link Circuit for an Open






• Measure the resistance of the dynamics sensor LOW data link circuit.

Is the resistance less than 5.0 ohms?

Yes

• Replace the dynamics sensor.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics . ABS Verification Test

No

• Repair the dynamics sensor high data Link circuit for an open.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test