U1003

U1003-ESP CAN C BUS PERFORMANCE

- When Monitored:
With the ignition on.
- Set Condition:
When the Anti-Lock Brake Module detects too many CAN Bus off events.

Possible Causes
WIRING HARNESS, TERMINAL, CONNECTOR DAMAGE
(D265) DYNAMICS SENSOR HIGH DATALINK CIRCUIT SHORTED TO GROUND, VOLTAGE, OR OPEN
(D264) DYNAMICS SENSOR LOW DATALINK CIRCUIT SHORTED TO GROUND, VOLTAGE, OR OPEN
DYNAMICS SENSOR
ANTI-LOCK BRAKE MODULE

Diagnostic Test
1. CHECK FOR A DTC U1003-ESP CAN C BUS PERFORMANCE

NOTE: 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 Fame 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: U1003-ESP CAN C BUS PERFORMANCE?
Yes >> Go To 2
No >>
Refer to the INTERMITTENT CONDITION diagnostic procedure. Component Tests and General Diagnostics
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

2. CHECK THE WIRING HARNESS, TERMINALS, AND CONNECTORS

NOTE: The Sensor Cluster is the same as the Dynamics sensor.

Check 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 - VER 1. ABS Verification Test
No >> Go To 3

3. CHECK (D265) DYNAMICS SENSOR HIGH DATALINK 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 (D265) Dynamics Sensor High Data Link circuit.
Is there any voltage present?
Yes >>
Repair the (D265) Dynamics Sensor High Datalink circuit for a short to voltage.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 4

4. CHECK THE (D265) DYNAMICS SENSOR HIGH DATALINK 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 (D265) Dynamics Sensor High Data Link circuit.
Is the resistance below 5.0 ohms?
Yes >>
Repair the (D265) Dynamics Sensor High Datalink circuit for a short to ground.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 5

5. CHECK THE (D265) DYNAMICS SENSOR HIGH DATALINK CIRCUIT FOR AN OPEN
Turn the ignition off.
Disconnect the Anti-Lock Brake Module harness connector.
Disconnect the Dynamics Sensor harness connector.
Measure the resistance of the (D265) Dynamics Sensor High Data Link circuit.
Is the resistance below 5.0 ohms?
Yes >> Go To 6
No >>
Repair the (D265) Dynamics Sensor High Datalink circuit for an open.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

6. CHECK THE (D264) DYNAMICS SENSOR LOW DATALINK CIRCUIT FOR A SHORT TO VOLTAGE
Turn the ignition on.
Measure the voltage of the (D264) Dynamics Sensor Low Data Link circuit.
Is there any voltage present?
Yes >>
Repair the (D264) Dynamics Sensor Low Datalink circuit for a short to voltage.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 7

7. CHECK THE (D264) DYNAMICS SENSOR LOW DATALINK CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
Measure the resistance between ground and the (D264) Dynamics Sensor Low Data Link circuit.
Is the resistance below 5.0 ohms?
Yes >>
Repair the (D264) Dynamics Sensor Low Datalink circuit for a short to ground.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 8

8. CHECK THE (D264) DYNAMICS SENSOR LOW DATALINK CIRCUIT FOR AN OPEN
Measure the resistance of the (D264) Dynamics Sensor Low Datalink circuit.
Is the resistance below 5.0 ohms?
Yes >> Go To 9
No >>
Repair the (D264) Dynamics Sensor Low Datalink circuit for an open.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

9. DYNAMICS SENSOR
Measure the voltage of the (D265) Dynamics Sensor High Data Link circuit at the Dynamics Sensor harness connector.
Measure the voltage of the (D264) Dynamics Sensor Low Data Link circuit at the Dynamics Sensor harness connector.
Is voltage within 2-3 volts on each circuit?
Yes >>
Replace the Dynamics Sensor.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >>
Replace the Anti-Lock Brakes Module.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test