U1003

U1003 - Electronic Stability Program CAN C Bus Performance






For a complete wiring diagram, refer to.

• When Monitored: With the ignition ON.

• Set Condition: If the anti lock brake module detects too many CAN Bus off events on the dynamics sensor data link circuits.






Test Step 1 - Test for a DTC U1003 - ESP Can C Bus Performance

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

• If present, diagnose and repair DTC U0125 Lost Communication With Dynamics Sensor before diagnosing this DTC.

• Turn the ignition ON.

• With the scan tool, read and record the DTCs.

• With the scan tool, read and record Environmental Data to help identify the conditions in which the DTC was set.

• With the scan tool, erase the DTCs.

• Start the engine.

• Attempt to operate the vehicle under conditions similar to which the DTC was set. It may be necessary to test drive the vehicle within the DTC monitoring and set conditions in order for this DTC to set.

• With the scan tool, read and record the DTCs

Does the scan tool display U1003 - ESP CAN C Bus Performance?

Yes

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

No

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

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

• The sensor cluster is the same as the dynamics sensor.

• Test the dynamics 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 anti lock brake module harness connector.

• Disconnect the dynamics sensor 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 - Test the Dynamics Sensor High Data Link Circuit for
a Short to Ground ]

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






• Turn the ignition OFF.

• Disconnect the anti lock brake module harness connector.

• Disconnect the dynamics sensor harness connector.

• 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

• Go to Test Step 9 => [ Test Step 9 - Replace Dynamics Sensor & Verify If DTC Is Still
Active ]

No

• Repair the dynamics sensor LOW data link circuit for an open.

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

Test Step 9 - Replace Dynamics Sensor & Verify If DTC Is Still Active

• Replace the dynamics sensor.

• Test drive the vehicle by turning the vehicle left or right in a curving manner at a velocity between 6 and 15 m.p.h. (10 and 25 km/h).

• Park the vehicle. With the scan tool, read ABS DTCs.

Does this DTC reset?

Yes

• Replace the anti lock brake module. .

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

No

• Test complete.