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 monitors the voltage level available to the EBCM/EBTCM. If the voltage drops below 10.5 volts, full performance of the ABS/TCS cannot be guaranteed. During ABS/TCS operation, there are several current requirements that will cause battery voltage to drop. The voltage is monitored prior to ABS/TCS operation in order to indicate good charging system condition and also during ABS/TCS operation when the voltage may drop significantly.

### Conditions for Setting the DTC

The vehicle speed is greater than 8 km/h (5 mph) and the battery and ignition voltages are less than 10.5 volts

### Action Taken When the DTC Sets

• | A DTC C1236 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

• | Thoroughly inspect the wiring and the connectors. Failure to carefully and fully inspect the wiring and the connectors can result in misdiagnosis. Misdiagnosis may cause replacement of parts without repairing the malfunction.

• | Inspect for other low voltage conditions.

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

• | The following conditions are other possible causes of low system voltage:

- | A charging system malfunction

- | Excessive parasitic drain

- | A weak battery

- | A faulty system ground

• | 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 for a good ground.

2. This step checks for battery voltage.

#### DTC C1236 Low 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 | Check the Charging System. Refer to Charging System Check in Engine Electrical. Is the charging system OK? | -- | Go to Step 3 | Go to Charging System Check in Engine Electrical
3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the EBCM/EBTCM harness connector.
3. Inspect the EBCM/EBTCM harness connector and the connector for damage or corrosion.

Is there any evidence of damage or corrosion?

--

Go to Step 7

Go to Step 4

4 |

1. Install the J 39700 universal pinout box using the J 39700-25 cable adapter between the EBCM/EBTCM harness connector and the EBCM/EBTCM.
2. Using the J 39200 DMM, measure the resistance between the J 39700 terminal B and a good ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 5

Go to Step 8

5 | Measure the voltage between the J 39700 terminals B and D. Is the voltage greater than the specified value? | 10.5 V | Go to Step 6 | Go to Battery Charging in Engine Electrical
6 |

1. Turn the ignition switch to the RUN position with the engine off.
2. Measure the voltage between the J 39700 terminals A and B.

Is the voltage greater than the specified value?

10.5 V

Go to Step 9

Go to Battery Charging in Engine Electrical

7 | Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Are the repairs complete? | -- | Go to Diagnostic System Check | --
8 | Repair the open or high resistance in CKT 1050. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Diagnostic System Check | --
9 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --