DTC C1237 High System Supply Voltage. Cadillac DeVille 1998

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 1998 🢒 DeVille 🢒 DTC 🢒 DTC C1237 High System Supply Voltage

The circuit detects high vehicle voltage levels to the solenoid relay. High voltage may cause damage to the system.

All of the following conditions occur:

•	The vehicle speed is greater than 8 km/h (5 mph).

•	The battery positive voltage (B+) is greater than 17 volts.

•	A malfunction DTC is stored.

•	The ABS/TCS/Stabilitrak® is disabled.

•	The ABS indicator is turned ON.

•	The TRACTION CONTROL indicator is turned ON.

•	The DIC displays the SERVICE STABILITY SYS message.

•	The condition for DTC is no longer present and you used scan tool Clear DTCs function.

•	The condition for DTC is no longer present and you used the On-Board Clear DTCs function.

•	The EBTCM does not detect the DTC in 50 drive cycles.

•	Test the battery for overcharging.

•	Thoroughly inspect the wiring and the connectors. Failure to thoroughly inspect the wiring and the connectors may result in misdiagnosis. Misdiagnosis may result in replacement of non-faulty components and reoccurrance of the malfunction.

•	If an intermittent malfunction is detected refer to Intermittents and Poor Connections .

•	Inspect for other low voltage conditions.

•	Test the charging system. Refer to Charging System Check in Engine Electrical.

The numbers below refer to step numbers on the diagnostic table.

Checks to see what the EBTCM is reading as the voltage.

Checks the actual battery voltage.

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic System Check performed?	--	Go to Step 2	Go to Diagnostic System Check
2	Turn off all of the accessories. Start the engine. Use a scan tool set to ABS/TCS DATA LIST in order to monitor the battery voltage while running the engine at approximately 2000 RPM. Is the voltage less than the specified value?	17 V	Go to Step 4	Go to Step 3
3	Use a J 39200 digital multimeter (DMM) in order to measure the actual battery voltage while running the engine at approximately 2000 RPM. Is the voltage less than the specified value?	17 V	Go to Step 4	Refer to Charging System Check in Engine Electrical.
4	Carefully test drive the vehicle above 8 km/h (5 mph). Does DTC C1237 reset as a current DTC?	--	Go to Step 5	Go to Diagnostic System Check
5	Replace the EBTCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair?	--	Go to Diagnostic System Check	--