Circuit Description
This DTC identifies a solenoid that cannot be energized due to an open in its circuitry, or a solenoid that is always energized due to a short to battery in its circuitry between the driver and the solenoid.
An open will not allow proper ABS operation, but the short to battery simply turns ON the solenoid. A path for base brakes is still allowed once the motor re-homes and the check ball is lifted off its seat during initialization.
Conditions for Setting the DTC
This DTC will set when the following conditions are met:
| • | The EBCM detects a short to voltage or open in CKT 9J01 and/or open in CKT 9V01. |
| • | This DTC can be set only when the solenoid is OFF. |
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 cause 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 |
Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |
2 |
Is the voltage within the range specified in the Value(s) column? | 0.0-2.0 V | ||
3 | Use the J 39200 in order to measure the resistance between the EBCM harness connector C1 terminal D13 and the RF ABS solenoid valve harness connector terminal A. Is the resistance within the range specified in the Value(s) column? | 0.0-2.0 ohms | ||
4 | Use the J 39200 in order to measure the resistance between the RF ABS solenoid connector terminal B and ground. Is the resistance within the range specified in the Value(s) column? | 0.0-2.0 ohms | ||
5 | Use the J 39200 in order to measure the resistance between the RF ABS solenoid terminals A and B. Is the resistance within the range specified in the Value(s) column? | 2.5-5.0 ohms | ||
6 |
Did DTC C1278 set in the past three ignition cycles? | -- | Go to Diagnostic System Check | |
7 | Repair the short to voltage in CKT 9J01. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
8 | Repair open or high resistance in CKT 9J01. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
9 |
Is the repair complete? | -- | Go to Diagnostic System Check | -- |
10 | Replace the RF ABS solenoid. Refer to Brake Solenoid Valve Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | -- |
11 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | -- |
