U0125
U0125 - Lost Communication with Dynamics Sensor
For a complete wiring diagram, refer to.
• When Monitored: With the ignition ON.
• Set Condition: If the anti lock brake module fails to receive Bus messages from the dynamics sensor.
Test step 1 - verify DTC is active
• If present, diagnose and repair DTC C2114 Dynamics Sensor Supply Voltage LOW or DTC C2115 Dynamics Sensor Supply Voltage HIGH before proceeding.
• Turn the ignition ON.
• With the scan tool, read and record the ABS 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 ABS 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 the ABS DTCs.
Does this DTC reset?
Yes
• Go to Test Step 2 => [ Test Step 2 - Inspect Related Wiring Harness, Terminals, and Connectors ]
No
• The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
• Perform the ABS Intermittent Condition Test. Refer to => Non-DTC Based Diagnostics. ABS Intermittent Condition Test
Test Step 2 - Inspect Related Wiring Harness, Terminals, and Connectors
• Visually inspect the related wiring harness. Look for any pinched, chafed, pierced, and partially broken wires.
• Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, and 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 Voltage On The Dynamics Sensor Supply Circuit ]
Test Step 3 - Test The Voltage On The Dynamics Sensor Supply Circuit
• Turn the ignition OFF.
• Disconnect the dynamics sensor harness connector.
• Turn the ignition ON.
• Measure the voltage across dynamics sensor supply circuit and dynamics sensor ground circuit.
Is the voltage more than 10 volts?
Yes
• Go to Test Step 10 => [ Test Step 10 - Test the Data Link Output ]
No
• Go to Test Step 4 => [ Test Step 4 - Dynamics Sensor Supply Circuit Short to Ground ]
Test Step 4 - Dynamics Sensor Supply Circuit Short to Ground
• Turn the ignition OFF.
• Disconnect the anti lock brake module harness connector.
• Measure the resistance between ground and the dynamics sensor supply circuit.
Is the resistance less than 5.0 Ohms?
Yes
• Repair the dynamics sensor supply 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 - Dynamics Sensor Supply Circuit Short to Voltage ]
Test Step 5 - Dynamics Sensor Supply Circuit Short to Voltage
• Turn the ignition ON.
• Measure the voltage of the dynamics sensor supply circuit.
Is there any voltage present?
Yes
• Repair the dynamics sensor supply circuit for a short to voltage.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
No
• Go to Test Step 6 => [ Test Step 6 - Dynamics Sensor Supply Circuit Open ]
Test Step 6 - Dynamics Sensor Supply Circuit Open
• Turn the ignition OFF.
• Measure the resistance of the dynamics sensor supply circuit.
Is the resistance less than 5.0 Ohms?
Yes
• Go to Test Step 7 => [ Test Step 7 - Test the Resistance between the Dynamics Sensor Ground
Circuit and Ground ]
No
• Repair the dynamics sensor supply circuit for an open.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
Test Step 7 - Test the Resistance between the Dynamics Sensor Ground Circuit and Ground
• Disconnect the dynamics sensor harness connector.
• Measure the resistance between the dynamics sensor ground circuit and ground.
Is the resistance less than 5.0 Ohms?
Yes
• Replace the anti lock brake module.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
No
• Go to Test Step 8 => [ Test Step 8 - Dynamics Sensor Ground Circuit Short to Voltage ]
Test Step 8 - Dynamics Sensor Ground Circuit Short to Voltage
• Turn the ignition OFF.
• Disconnect the anti lock brake module harness connector.
• Turn the ignition ON.
• Measure the voltage of the dynamics sensor ground circuit.
Is there any voltage present?
Yes
• Repair the dynamics sensor ground circuit for a short to voltage.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
No
• Go to Test Step 9 => [ Test Step 9 - Dynamics Sensor Ground Circuit Open ]
Test Step 9 - Dynamics Sensor Ground Circuit Open
• Turn the ignition OFF.
• Measure the resistance of the dynamics sensor return circuit between the dynamics sensor and the anti lock brake module.
Is the resistance less than 5.0 Ohms?
Yes
• Replace the anti lock brake module.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
No
• Repair the dynamics sensor ground circuit for an open.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
Test Step 10 - Test the Data Link Output
• Measure the voltage of the data links circuits the dynamics sensor high data link circuit will measure a minimum of 3 volts and the dynamics sensor LOW data link circuit will measure a minimum of 2 volts.
Is the voltage within specifications?
Yes
• Replace the dynamic sensor.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
No
• Go to Test Step 11 => [ Test Step 11 - Test the Dynamics Sensor High Data Link Circuit for
a Short to Voltage ]
Test Step 11 - Test the Dynamics Sensor High Data Link Circuit for a Short to Voltage
• Disconnect the anti lock brakes 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 12 => [ Test Step 12 - Test the Dynamics Sensor High Data Link Circuit for
a Short to Ground ]
Test Step 12 - Test the Dynamics Sensor High Data Link Circuit for a Short to Ground
• Turn the ignition OFF.
• Measure the resistance of the dynamics sensor high data Link circuit between ground and the dynamics sensor harness connector.
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 13 => [ Test Step 13 - Test the Dynamics Sensor High Data Link Circuit for
an Open ]
Test Step 13 - Test the Dynamics Sensor High Data Link Circuit for an Open
• Measure the resistance of the dynamics sensor high data link circuit between the dynamics sensor harness connector and the anti lock brakes module harness connector.
Is the resistance less than 5.0 Ohms?
Yes
• Go to Test Step 14 => [ Test Step 14 - 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 14 - 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 15 => [ Test Step 15 - Test the Dynamics Sensor LOW Data Link Circuit for
a Short to Ground ]
Test Step 15 - Test the Dynamics Sensor LOW Data Link Circuit for a Short to Ground
• Turn the ignition OFF.
• Measure the resistance of the dynamics sensor LOW data link circuit between ground and the dynamics sensor harness connector.
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 16 => [ Test Step 16 - Test the Dynamics Sensor LOW Data Link Circuit for
an Open ]
Test Step 16 - Test the Dynamics Sensor LOW Data Link Circuit for an Open
• Measure the resistance of the dynamics sensor LOW data link circuit between the dynamics sensor harness connector and the anti lock brake module harness connector.
Is the resistance less than 5.0 Ohms?
Yes
• Replace the anti lock brake module.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test
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