C1237

Circuit Description
DTC C1237 detects high vehicle voltage levels prior to any required motor movement (initialization or ABS). Damage to the system may occur if excessive voltage exists.

Conditions for Setting the DTC
DTC C1237 can set only if the vehicle's speed is greater than 5 km/h (3 mph).
A malfunction exists if the switched battery voltage is greater than 17 volts.

Action Taken When the DTC Sets
^ A malfunction DTC stores.
^ The ABS disables.
^ The ABS warning indicator turns ON.

Conditions for Clearing the DTC
^ The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
^ 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

Diagnostic Aids
The following conditions may cause an intermittent malfunction:
^ A poor connection
^ Rubbed-through wire insulation
^ A broken wire inside the insulation
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.
Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal-o-wiring connections
^ Physical damage to the wiring harness

Test Description
3. This test isolates the malfunction to either the EBCM or the charging system.
4. This test determines if the malfunction is caused by the EBCM.





DTC C1237 High System Supply Voltage