Circuit Description
The electronic brake control module (EBCM) monitors the deceleration of the vehicle for Antilock Brake System (ABS) operation.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1234 Yaw Rate Sensor Performance
Conditions for Running the DTC
DTC C1234 can be set anytime the ignition is in the ON position.
Conditions for Setting the DTC
The EBCM detects malfunction in the deceleration sensor.
Action Taken When the DTC Sets
| • | The ABS is disabled. |
| • | The ABS warning indicator turns ON. |
| • | The traction control and vehicle stability control (VSC) is disabled. |
| • | The VSC warning indicator turns ON. |
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
| • | An open or high resistance in the deceleration voltage circuit |
| • | An open or high resistance in the deceleration sensor ground circuit |
| • | A deceleration sensor malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
2 | Is U0073, U0123, U0124, or U0126 also set? | -- | Go to Step 3 | |||||||
3 |
Is the voltage within the specified range? | 10-14 V | Go to Step 4 | Go to Step 5 | ||||||
Test the deceleration sensor ground circuits of the electronic brake control module (EBCM) for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 6 | |||||||
5 | Locate and repair the following in the ignition positive voltage circuit of the deceleration sensor.
Did you find and correct the condition? | -- | Go to Step 7 | -- | ||||||
6 | Replace the deceleration sensor. Refer to Deceleration Sensor Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- | ||||||
7 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||
