Circuit Description
Ignition voltage is supplied to terminal 86 of the Electronic Brake Control Relay. The above condition enables the EBCM to energize the pullin coil by completing the ground circuit at connector terminal A11 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.
Conditions for Setting the DTC
DTC C1214 can set anytime after the EBCM commands the Electronic Brake Control Relay ON. The command occurs during the three second bulb check.
DTC C1214 monitors the availability of current/voltage to the motors.
The above malfunction indicates voltage is not available. The malfunction will not allow ABS operation.
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | ABS is disabled. |
| • | The amber ABS warning indicator is turned 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 a malfunction:
| • | A poor connection |
| • | Rubbed-through wire insulation |
| • | A broken wire inside the insulation |
| • | Open ABS fuse |
| • | Malfunctioning Electronic Brake Control Relay (contacts open/high resistance) |
| • | Poor terminal contacts from the relay box to the Electronic Brake Control Relay (look for spread terminals) |
| • | Malfunctioning electrical circuits (open or high resistance) between the Electronic Brake Control Relay and the EBCM and/or between the fuse box and the Electronic Brake Control Relay |
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.
Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Improperly formed or damaged terminals |
| • | Poor terminal-to-wiring connections |
| • | Physical damage to the wiring harness |
Vibration and Temperature Effects
| • | Use the following procedure in order to inspect for vibration effects by performing the Relay Test function of the Scan Tool: |
| 1. | With the Relay Test commanded on, lightly tap the top and sides of the Electronic Brake Control Relay while monitoring the Electronic Brake Control Relay voltage. |
| 2. | If the Electronic Brake Control Relay voltage changes significantly, replace the Electronic Brake Control Relay. |
| • | If DTC C1214 only sets when the vehicle is initially started in cold ambient conditions (temperature less than 0°C - 32°F), replace the Electronic Brake Control Relay. |
Test Description
-
This test checks to see if the EBCM is sensing battery voltage at terminal C.
-
This test ensures that battery voltage is available at the electronic brake control relay.
-
This test checks for excessive resistance in the switched battery input circuit.
-
This test checks for proper operation of the electronic brake control relay.
-
This test determines if the malfunction is caused by the EBCM.
Step | Action | Value(s) | Yes | No | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual. | ||||||||||||||||||
1 | Was A Diagnostic System Check-ABS performed? | -- | ||||||||||||||||
2 |
Do not start the engine. Is DTC C1216 present (either as a current DTC or a history DTC)? | -- | ||||||||||||||||
Is the voltage within the specified range? | Battery Voltage | |||||||||||||||||
Is the voltage within the specified range? | Battery Voltage | |||||||||||||||||
Is the resistance within the specified range? | 0-2 ohms | |||||||||||||||||
Is the voltage within the specified range? | Battery Voltage | |||||||||||||||||
7 |
Are there signs of poor terminal contact, corrosion, or damaged terminal(s)? | -- | ||||||||||||||||
8 | Remove and inspect the ABS fuse. Is the ABS fuse open? | -- | ||||||||||||||||
Use the J 39200 in order to measure the voltage between the ABS fuse terminal and ground. Is the voltage within the specified range? | Battery Voltage | Go to Power Distribution Schematics in Wiring Systems | ||||||||||||||||
10 | Repair the open or high resistance in the WHT wire between the Relay Box and the EBCM. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||||||||||||
11 | Inspect the Switched Battery input circuit for a short to ground. Refer to Testing for Short to Ground in Wiring Systems. Repair as necessary. Replace the ABS fuse. Is the repair complete? | -- | -- | |||||||||||||||
12 | Repair the open or high resistance in the WHT/BLU wire between the Fuse Box and the Relay Box. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||||||||||||
13 | Replace the Electronic Brake Control Relay. Refer to Electronic Brake Control Relay Replacement . Is the repair complete? | -- | -- | |||||||||||||||
14 | Replace all of the terminals the connectors that exhibit signs of poor terminal contact, corrosion, or damaged terminal(s). Is the repair complete? | -- | -- | |||||||||||||||
15 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | -- | |||||||||||||||
16 | The malfunction is intermittent or is not present at this time. Refer to Diagnostic Aids for more information. Is the action complete? | -- | System OK | -- | ||||||||||||||
