C1236

DTC C1236: Low System Voltage (Part 1 Of 2):

DTC C1236: Low System Supply Voltage (Part 2 Of 2):

DTC C1236: EBCM Voltage Schematic:

CIRCUIT DESCRIPTION
This DTC is used to monitor the voltage level available to the EBCM. If the voltage drops below 11.0 volts, full performance of the ABS system cannot be guaranteed. During ABS operation, there are several current requirements that will cause battery voltage to drop. Because of this, voltage is monitored prior to ABS operation (to indicate good charging system condition) and also during ABS operation when voltage may drop significantly.

CONDITIONS FOR SETTING THE DTC
DTC C1236 can only be set if the vehicle's speed is greater than 5 km/h (3 mph). If both the switched battery and switched ignition voltages are less than 11.2 volts non-ABS or less than 8.3 volts ABS, a malfunction exists.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS is disabled, and the ABS indicator lamp is turned ON.

CONDITIONS FOR CLEARING THE DTC
Conditions for the malfunction are no longer present and the scan tool CLEAR DTCs function is used. One hundred ignition switch key cycles have passed with no malfunctions detected.

DIAGNOSTIC AIDS
An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation or a wire that is broken inside the insulation. The frequency of the malfunction can be checked by using the ENHANCED DIAGNOSTIC function of the scan tool. Any circuitry that is suspected of causing the intermittent complaint should be thoroughly checked for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connechons or physical damage to the wiring harness.

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
7. Checks the continuity of the power feed circuit
from the battery to the relay.