Circuit Description
Ignition voltage is supplied to terminal 86 of the Electronic Brake Control Relay. The above enables the EBCM to energize the pullin coil by completing the ground circuit at connector terminal 2 of the EBCM. The magnetic field created closes the Electronic Brake Control Relay contacts. The magnetic field also allows battery voltage and current through the Electronic Brake Control Relay terminal 30 to be supplied to the EBCM through connector terminal C. Connector terminal C supplies power to the EBCM, which supplies power to the motors and solenoids.
Conditions for Setting the DTC
DTC C1218 can set after the EBCM commands the Electronic Brake Control Relay on.
This test monitors the availability of voltage to the EBCM at terminal 2.
DTC C1286 is set with DTC C1218 if the rear channel is not expected to be in the home position.
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 DTC(s) 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
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.
Clear the DTCs after completing the diagnosis. Test drive the vehicle for three drive cycles in order to verify that the DTC does not reset. Use the following procedure in order to complete one drive cycle:
- Start the vehicle.
- Drive the vehicle over 16 km/h (10 mph).
- Stop the vehicle.
- Turn the ignition switch to the OFF position.
Step | Action | Value(s) | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual. | ||||||||||||||
1 | Was the Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |||||||||||
2 |
Do not start the engine. Does the Scan Tool indicate that the Electronic Brake Control Relay is off, and is the voltage equal to or greater than the specified voltage? | 10 V | ||||||||||||
3 |
Do not start the engine. Is the voltage within the specified voltage? | 0-1 V | ||||||||||||
4 |
Is the resistance equal to or greater than the specified range? | 65-95 ohms | ||||||||||||
5 | Use the J 39200 in order to measure the resistance between the Electronic Brake Control Relay terminal 30 and the Electronic Brake Control Relay terminal 87. Is the resistance within the specified range? | OL (Infinite) | ||||||||||||
6 |
Are there signs of poor terminal contact, corrosion, or damaged terminals? | -- | ||||||||||||
7 |
Do not start the engine. Does DTC C1218 set as a current DTC? | -- | ||||||||||||
8 | Replace all of the terminals or connectors that exhibit signs of poor terminal contact, corrosion, or damaged terminal(s). Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||||||
9 | Repair the short to voltage in CKT 1632. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||||||
10 | Replace the Electronic Brake Control Relay. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||||||
11 | Replace the EBCM. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||||||
12 | The malfunction is intermittent or is not present at this time. Refer to Diagnostic Aids for more information. | -- | -- | -- | ||||||||||
