Circuit Description
This DTC identifies a possible malfunction within the electronic brake control module (EBCM).
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1604 ECU Malfunction
Conditions for Running the DTC
Ignition is in the ON position.
Conditions for Setting the DTC
DTC C1604 will set when a possible internal component/microprocessor problem may exist.
Action Taken When the DTC Sets
| • | DTC C1604 is stored. |
| • | The ABS and de-coupled dynamic rear proportioning (DDRP) are disabled |
| • | The ABS warning lamp and brake warning lamp are turned ON. |
| • | The solenoid relay opens, removing power from the pump motor and solenoids. |
Conditions for Clearing the DTC
| • | If the conditions that set DTC C1604 are no longer present, the DTC may be cleared by using the proper scan tool. |
| • | The DTC that has not occurred in 100 drive cycles will be cleared from the history data. |
Diagnostic Aids
| • | When DTC C1604 is displayed on the scan tool, it should be followed by 2 additional numbers, which should be documented along with any other DTCs that may be displayed. |
| • | Repair the low voltage, driveability, or other electrical complaints first, prior to performing DTC C1604. |
| • | Ensure the integrity of the connection between the EBCM and the brake pressure modulator valve (BPMV) is secure, tight, and free of corrosion, leaks, and/or damage. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the scan tool display any DTCs set in current or history data other than DTC C1604? | Go to Step 3 | |
3 |
Were any problems found? | Go to Step 4 | Go to Step 5 |
4 | Repair as needed. Did you find and correct the condition? | Go to Step 6 | -- |
5 | Replace the EBCM. Refer to Brake Pressure Modulator Valve Assembly Replacement . Did you complete the replacement? | Go to Step 6 | -- |
6 |
Does the DTC reset? | Go to Step 2 | System OK |
