For 1990-2009 cars

The ABS control module (EBTCM) functions properly within a specified range of voltage. During ABS operation there are current requirements that will cause the system voltage to drop. Because of this, the EBTCM continuously monitors system voltage.

### DTC Parameters

DTC C0899 will set if:

Vehicle speed is greater than 8 km/h (5 mph), ignition voltage is less than or equal to 11.2 volts, the solenoid relay is commanded on and one of the following conditions exists for 0.72 seconds:

• | System is not in ABS, (pump off) and system voltage is less than or equal to 11.2 volts.

• | During initialization system voltage is less than or equal to 11.2 volts.

• | System is in ABS stop (pump running) system voltage is less than or equal to 9.6 volts.

When this trouble code sets, the EBTCM will disable ABS and turn On the antilock telltale.

Dynamic rear proportioning (DRP) will only have the hold function unless system voltage is less than 8 volts, then DRP will be disabled and the RED brake telltale turned on.

### Diagnostic Aids

Check for the following conditions:

• | Poor connection or damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the battery voltage display on the scan tool while moving connectors and wiring related ABS dash harness, and engine harness. A change in display will indicate the location of fault.

• | For complete information and additional diagnostics for the vehicle charging system, refer to Starting and Charging.

Possible causes for DTC C0899 to set:

• | Charging system malfunction

• | Excessive battery draw

• | Weak battery

• | Loose or corroded ground

• | Loose or corroded battery terminals