Circuit Description
The EBCM receives the rear wheel speed signal from the Vehicle Control Module (VCM). The rear wheel speed signal originates from the Vehicle Speed Sensor (VSS) which is connected to the VCM. When the vehicle is not moving, the VCM will have 12 VDC present on the circuit. The EBCM checks for this voltage when the vehicle is not moving.
Conditions for Setting the DTC
EBCM not seeing the correct voltage level from the VCM at startup.
Action Taken When the DTC Sets
| • | The ABS indicator lamp turns on |
| • | The ABS disables |
DTC C0235 is a Condition Latched DTC, which indicates that the above actions are true until the condition is cleared.
Conditions for Clearing the DTC
| • | Repair the conditions responsible for setting the DTC |
| • | Use the Scan Tool Clear DTCs function |
Diagnostic Aids
Before performing any diagnostics on the ABS, resolve any Vehicle Speed Sensor (VSS) DTC's currently set in the VCM.
This DTC can be set by a faulty EBCM or a fault in CKT 696.
If the voltage readings are low or varying, the battery or charging system could be the cause. Check these areas before replacing any components. In addition, any of the following conditions may cause an intermittent malfunction:
| • | A poor connection |
| • | Wire insulation that is rubbed through |
| • | A wire breaks inside the insulation |
Thoroughly check any circuitry that is suspected of causing the intermittent complaint for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal to wiring connections |
| • | Physical damage to the wiring harness |
Test Description
The numbers below refer to the steps in the diagnostic table:
-
This step uses the voltage output from the VCM (gas) or Vehicle Speed Sensor Buffer (diesel) to check the 1827 CKT.
-
This step checks the CKT 1827 for proper resistance.
-
This step checks for a short in the wiring between the ECBM and the PCM.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | |
Is the voltage measurement equal to or greater than the specified value? | 10 V | Go to Step 4 | Go to Step 3 | |
Is the resistance measurement within the specified range? | 0-2 ohms | Go to Step 5 | Go to Step 8 | |
4 |
Did DTC set? | -- | Go to Step 6 | Go to Step 7 |
Using the J 39200 , measure the resistance between the EBCM 10-way connector terminal E and ground. Is the resistance measurement within the specified range? | OL | Go to Engine Controls for Vehicle Speed Sensor Diagnosis | Go to Step 9 | |
6 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | -- | |
7 | Malfunction is intermittent.
Is the repair complete? | -- | -- | |
8 | Repair the open in CKT 696. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
9 | Repair short to ground in CKT 696. Refer to Wiring Repairs . Is the repair complete? | -- | -- |
