Circuit Description
The EBCM will monitor the on/off state of each solenoid and will recognize when the ABS is in pressure decrease too long. This fault indicates that the EBCM was unable to decrease brake pressure enough to a certain wheel to prevent excessive wheel slip. This fault can cause erratic ABS or no ABS operation.
Conditions for Running the DTC
The vehicle is in an ABS stop.
Conditions for Setting the DTC
Any wheel is releasing for greater than 1.0 second while the wheel speed at the wheel is less than 5.0 k/ph (3.0 mph).
Action Taken When the DTC Sets
| • | ABS/TCS is disabled. |
| • | ABS/TCS Indicators are turned on. |
Conditions for Clearing the DTC
| • | Condition for DTC is no longer present and scan tool clear DTC function is used. |
| • | 100 ignition cycles have passed with no DTCs detected. |
Diagnostic Aids
| • | Possible causes for DTC C1216 to set are: |
| - | A contaminated hydraulic unit. |
| - | An intermittent wheel speed sensor. |
| - | A sticking solenoid. |
| - | Excessive brake drag or high resistance in base brake system. |
| - | Suspension system irregularities. |
| • | It is very important that a thorough inspection of the brake fluid condition, wiring and connectors be performed. Failure to carefully and fully inspect brake fluid condition, wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. |
| • | If an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittents and Poor Connections in Wiring Systems. |
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | |||||||
2 |
Does the scan tool display any other ABS/TCS DTCs relating to wheel speed sensor or solenoid valve operation? | -- | Go to Step 3 | |||||||
3 | With a scan tool, monitor all of the wheel speed sensor in the ABS/TCS/TIM Data Display while decelerating the vehicle from 56 to 0 k/ph (35 to 0 mph). Do any of the wheel speeds indicate erratic or intermittent operation? | -- | Go to Diagnostic Trouble Code (DTC) List/Type for Excessive Wheel Speed Variation for the affected wheel | Go to Step 4 | ||||||
4 | Inspect the base brake system for the following conditions:
Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 5 | ||||||
5 |
Does the DTC reset as a current DTC? | -- | Go to Step 6 | System OK | ||||||
6 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- | ||||||
7 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
