• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Sensor B+ | U1826 72 | U1826 7F, U1826 72 | -- | -- |
Yaw Sensor Can Bus High Serial Data | U1826 72, U1826 7F | U1826 71, U1826 72, U1826 7F | U1826 71 | U1826 71 |
Yaw Sensor Can Bus Low Serial Data | U1826 72 | U1826 71, U1826 72, U1826 7F | U1826 71 | U1826 7F |
Low Reference | -- | U1826 71, U1826 72, U1826 7F | -- | U1826 71 |
The yaw rate and the lateral accelerometer sensors are combined into one sensor, external to the electronic brake control module (EBCM). The vehicle stability enhancement system (VSES) uses the lateral accelerometer input when calculating the desired yaw rate. The yaw rate/lat sensor communicates with the EBCM via discrete CAN Bus High and CAN Bus Low serial data circuits.
Ignition ON
• | The EBCM detects a short to ground, open/high resistance on the yaw/rate sensor B+ circuit. |
• | The EBCM detects a short to B+, a short to ground, or open/high resistance on the CAN Bus high serial data circuit. |
• | The EBCM detects a short to B+, or an open/high resistance on the CAN Bus low serial data circuit. |
• | The EBCM detects an or an open/high resistance on the low reference circuit. |
• | The EBCM disables VSES, if equipped, and traction control system (TCS) will not function. |
• | The EBCM sends a serial data message to illuminate a warning indicator/message that a fault is detected. |
• | The condition for the DTC is no longer present. |
• | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Antilock Brake System Schematics
Control Module References for scan tool information
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM. |
• | CAN bus high serial data circuit terminal 33 |
• | CAN bus low serial data circuit terminal 21 |
⇒ | If greater than the specified value, test the appropriate serial data circuit for a short to voltage. |
• | CAN bus high serial data circuit terminal 33 |
• | CAN bus low serial data circuit terminal 21 |
⇒ | If not the specified value, test the appropriate serial data circuit for a short to ground. |
• | CAN bus high serial data circuit terminal 33 at the EBCM harness connector and terminal 2 at the yaw/rate sensor. |
• | CAN bus low serial data circuit terminal 21 at the EBCM harness connector and terminal 3 at the yaw/rate sensor. |
⇒ | If greater than the specified range, test the appropriate serial data circuit for an open/high resistance. |
⇒ | If not the specified value, test the serial data circuits for a short to each other. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for module replacement, setup, and programming |