U1004

U1004-CAN C BUS TRANSMIT PERFORMANCE





For the Anti-Lock Brake System circuit diagram. Refer to SCHEMATICS AND DIAGRAMS.

When Monitored
With the ignition on.

Set Condition
When the Anti-Lock Brake Module detects invalid CAN message from the Dynamics Sensor.

Possible Causes
- WIRING HARNESS, TERMINAL, CONNECTOR DAMAGE
- (D52) DYNAMICS SENSOR HIGH DATALINK CIRCUIT SHORTED TO GROUND, VOLTAGE, OR OPEN
- (D51) DYNAMICS SENSOR LOW DATALINK CIRCUIT SHORTED TO GROUND, VOLTAGE, OR OPEN
- DYNAMICS SENSOR

Diagnostic Test
1. CHECK FOR A DTC U1004-CAN C BUS TRANSMIT 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: U1004-CAN C BUS TRANSMIT PERFORMANCE?
Yes >> Go To 2
No >> Refer to the INTERMITTENT CONDITION diagnostic Procedure.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
2. CHECK THE WIRING HARNESS, TERMINALS, AND CONNECTORS





Check 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 - VER 1. ABS Verification Test
No >> Go To 3
3. CHECK THE (D52) 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.
Using a 12-volt test light connected to ground, check the (D52) Dynamics Sensor High Datalink circuit.

Does the test light illuminate brightly?
Yes >> Repair the (D52) 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 (D52) 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.
Using a 12-volt test light connected to 12-volts, check the (D52) Dynamics Sensor High Datalink circuit.

Does the test light illuminate brightly?
Yes >> Repair the (D52) 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 (D52) 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.
Connect a jumper wire between the (D52) Dynamics Sensor High Datalink circuit and ground.
Using a 12-volt test light connected to 12-volts, check the (D52) Dynamics Sensor High Datalink circuit.

Does the test light illuminate brightly?
Yes >> Go To 6
No >> Repair the (D52) Dynamics Sensor High Datalink circuit for an open.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
6. CHECK THE (D51) DYNAMICS SENSOR LOW 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.
Using a 12-volt test light connected to ground, check the (D51) Dynamics Sensor Low Datalink circuit.

Does the test light illuminate brightly?
Yes >> Repair the (D51) 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 (D51) DYNAMICS SENSOR LOW 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.
Using a 12-volt test light connected to 12-volts, check the (D51) Dynamics Sensor Low Datalink circuit.

Does the test light illuminate brightly?
Yes >> Repair the (D51) 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 (D51) DYNAMICS SENSOR LOW DATALINK CIRCUIT FOR AN OPEN





Turn the ignition off.
Disconnect the Anti-Lock Brake Module harness connector.
Disconnect the Dynamics Sensor harness connector.
Turn the ignition on.
Connect a jumper wire between the (D51) Dynamics Sensor Low Datalink circuit and ground.
Using a 12-volt test light connected to 12-volts, check the (D51) Dynamics Sensor Low Datalink circuit.

Does the test light illuminate brightly?
Yes >> Replace the Dynamics Sensor in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Repair the (D51) Dynamics Sensor Low Datalink circuit for an open.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test