Circuit Description
The electronic brake control module (EBCM) supplies 5 volts to the yaw rate sensor/lateral accelerometer. When the vehicle is not moving, or is being driven in a stable, straight line, yaw rate is 0 degrees/second and the yaw rate sensor signal voltage is very near 2.5 volts. This is referred to as sensor bias voltage. Performing a turning maneuver causes the yaw rate sensor signal voltage to increase, or decrease, depending on the direction of the turn. The sharper the turn, the greater the change in signal voltage. Since the yaw rate signal is affected by temperature, the EBCM also monitors a Hz frequency signal from the yaw rate sensor/lateral accelerometer which is proportionate to the approximate temperature of the yaw rate sensor.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0196 Yaw Rate Circuit
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The vehicle stability enhancement system (VSES) sensors have been successfully initialized or the message center has displayed the stability system disabled message due to an unsuccessful initialization attempt. Refer to ABS Description and Operation for a complete explanation of VSES sensor initialization. |
| • | The vehicle is being driven relatively straight and level at a speed greater than 11 km/h (7 mph), before performing a stable turning maneuver. |
Conditions for Setting the DTC
Any of the following conditions may cause the DTC to set:
| • | Open yaw rate sensor circuitry is detected. |
| • | Shorted yaw rate sensor circuitry is detected. |
| • | An erratic yaw rate sensor signal is detected. |
| • | The EBCM detects that the yaw rate sensor signal does not correspond with signals from other sensors. |
| • | The EBCM detects that the yaw rate sensor frequency signal is not within the valid range. |
Action Taken When the DTC Sets
| • | The EBCM disables the VSES. |
| • | The stability indicator turns ON. |
Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.
Diagnostic Aids
| • | The following scenario may cause this DTC to set when no actual malfunction exists: |
| - | The vehicle is driven in a straight line in reverse at a speed greater than 13 km/h (8 mph). |
| - | The transmission is shifted into neutral while the vehicle continues to coast backward. |
| - | A turning maneuver is performed after the above conditions are met and the vehicle speed is still greater than 13 km/h (8 mph). |
| • | This DTC may also set falsely if the yaw rate sensor is replaced without first following the diagnostic table below. Whenever a new yaw rate sensor is installed, the old sensor must be disconnected, the ignition turned ON for 5 seconds and then OFF, and then the new sensor connected. |
| • | Inspect the vehicle for proper wheel alignment. Ensure the vehicle does not pull toward the left or right while driving straight forward on a level surface. |
| • | Communicate with the customer to determine the conditions under which the message center displays the service stability system message. Learning the conditions under which the DTC sets may help you duplicate the failure. |
| • | Use the Snapshot function on the scan tool in order to assist you in locating an intermittent malfunction. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the sensor 5-volt reference circuitry and ground circuit.
-
This step tests the sensor signal circuit for an open or high resistance.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Important:
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||||||||
1 | Did you perform the ABS Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
2 |
Does the DTC reset? | -- | Go to Step 3 | Go to Diagnostic Aids | ||||||
Does the voltage measure greater than the specified value? | 4.75 V | Go to Step 5 | Go to Step 4 | |||||||
Test the yaw rate signal circuit for the following conditions:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 6 | |||||||
5 |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 7 | ||||||
6 | Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 | ||||||
7 |
Important: Replace the lateral accelerometer/yaw rate sensor, Refer to EBCM reprogramming to verify current calibration (enabling Yaw Rate Sensor Recalibration). Use a scan tool to Recalibrate the Yaw Rate Sensor. Replace the lateral accelerometer/ yaw rate sensor. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- | ||||||
8 |
Important: Following EBCM replacement, perform the set-up procedure for the EBCM. Use the scan tool to perform the Tire Size Calibration procedure. Replace the EBCM. Refer to Control Module References . Did you complete the replacement? | -- | Go to Step 9 | -- | ||||||
9 |
Does the DTC reset? | -- | Go to Step 3 | System OK | ||||||
