For 1990-2009 cars
ABS Components
Cell 44: PWR, GND, Pump Motor, Valve Solenoids, and Stoplamp/BTSI Switch
Cell 10: Battery and Underhood Fuse Blocks
Cell 10: MISC LGT, COOL FNS, C/LTR/RDO/CLSTR/MISC, ABS SOL and ABSMOT Fuses
Cell 10: ABS/CCR and CLG FAN/TCC Fuses
Handling ESD Sensitive Parts Notice

### Circuit Description

This circuit is designed to detect high vehicle voltage levels to the solenoid relay. High voltage may cause damage to the system.

### Conditions for Setting the DTC

The vehicle speed is greater than 8 km/h (5 mph) and the battery voltage is more than 17.0 volts

### Action Taken When the DTC Sets

• | A DTC C1237 is stored

• | The ABS/TCS is disabled

• | The ABS and TRACTION OFF indicators are turned on

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present and the scan tool clear DTC function is used

• | 50 ignition cycles have passed with no DTCs detected

### Diagnostic Aids

• | Inspect the battery for overcharging

• | If an intermittent malfunction exists, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

### Test Description

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

1. This step checks to see what the EBCM/EBTCM is reading as the voltage.

2. This step checks the actual battery voltage.

#### DTC C1237 High System Supply Voltage

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 |

1. Turn all accessories off.
2. Start the engine.
3. Using the scan tool, select the ABS/TCS DATA LIST.
4. Monitor the battery voltage while running the engine at about 2000 rpm.

Is the voltage less than the specified value?

17.0 V

Go to Step 5

Go to Step 3

3 | Using the J 39200 DMM, check the actual battery voltage while running the engine at about 2000 rpm. Is the voltage less than the specified value? | 17.0 V | Go to Step 4 | Go to Charging System Check in Engine Electrical
4 | Test drive the vehicle above 8 km/h (5 mph). Does DTC C1237 reset? | -- | Go to Step 5 | Go to Diagnostic System Check
5 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --