For 1990-2009 cars
ABS Components
Antilock Brake System Schematics
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The EBCM exchanges serial data through EBCM harness connector terminal 12.

Connector terminal 4 supplies the switched ignition voltage to the EBCM.

Connector terminal 13 supplies the battery voltage to the EBCM.

Connector terminal C supplies the switched battery voltage to the EBCM.

Connector Terminal D provides the ground for the EBCM.

### Diagnostic Aids

Communication with the EBCM is not possible when excessive resistance exists in the following components:

• | The ground

• | The power supply circuits

If communication with the EBCM is not possible, perform the following actions:

• | Verify that the EBCM ground connection is good.

• | Verify that no excessive resistance exists in any of the power supply circuits.

### Test Description

1. This test checks for high resistance in the EBCM ground circuit.

2. This test checks for an open in the EBCM battery feed circuit.

3. This test checks for an open or high resistance in the EBCM switched ignition circuit.

4. This test checks for an open or high resistance in the EBCM serial data circuit.

5. This test checks for a short to ground in the EBCM serial data circuit.

6. This test checks for a short to ground in the EBCM battery feed circuit.

7. This test checks for a short to ground in the EBCM switched ignition circuit.

#### No Communication With 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 the ABS Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 | Verify the correct connection of the Scan Tool to the DLC. Is connection of the Scan Tool to the DLC correct? | -- | Go to Step 3 | Go to Step 13
3 |

1. Turn the ignition switch to the OFF position.
2. Remove and inspect the ABS BATT Fuse (10A).

Is the fuse open?

--

Go to Step 11

Go to Step 4

4 |

1. Install the ABS BATT fuse (10A).
2. Remove the ABS IGN Fuse (10A).

Is the fuse open?

--

Go to Step 12

Go to Step 5

5 |

1. Install the ABS IGN Fuse (10A).
2. Disconnect the EBCM connector.
3. Use the J 39200 in order to measure the resistance between the EBCM connector terminal D and ground.

Is the resistance within the specified range?

0-2 ohms

Go to Step 6

Go to Step 18

6 |

1. Disconnect the EBCM connector.
2. Use the J 39200 in order to measure voltage between the EBCM connector terminal 13 and ground.

Is the voltage equal to or greater than the specified voltage?

10 V

Go to Step 7

Go to Step 19

7 |

1. Turn the ignition switch to the ON position.

Do not start the engine.

2. Use the J 39200 in order to measure voltage between the EBCM connector terminal 4 and ground.

Is the voltage equal to or greater than the specified voltage?

10 V

Go to Step 8

Go to Step 20

8 |

1. Turn the ignition switch to the OFF position.
2. Use the J 39200 in order to measure the resistance between the EBCM connector terminal 12 and the DLC terminal 2.

Is the resistance within the specified range?

0-2 ohms

Go to Step 9

Go to Step 21

9 | Use the J 39200 in order to measure the resistance between the EBCM connector terminal 12 and ground. Is the resistance within the specified range? | OL (Infinite) | Go to Step 10 | Go to Step 22
10 | Inspect the EBCM connector for the following conditions:

• | Poor terminal contact

• | Terminal corrosion

• | Damaged terminals

Are there signs of poor terminal contact, terminal corrosion, or damaged terminals?

--

Go to Step 23

Go to Step 24

11 |

1. Disconnect the EBCM connector.
2. Use the J 39200 in order to measure the resistance between the EBCM connector terminal 13 and ground.

Is the resistance within the specified range?

OL

(Infinite)

Go to Step 14

Go to Step 15

12 |

1. Disconnect the EBCM connector.
2. Use the J 39200 in order to measure the resistance between the EBCM connector terminal 4 and ground.

Is the resistance within the specified range?

OL

(Infinite)

Go to Step 16

Go to Step 17

13 | Disconnect and reconnect the Scan Tool in order to ensure a good connection. Is the Scan Tool correctly connected? | -- | Go to Diagnostic System Check - ABS | --
14 | Replace the ABS BATT Fuse. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
15 | Repair the short to ground in CKT 1640 and replace the ABS BATT Fuse. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
16 | Replace the ABS IGN Fuse. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
17 | Repair the short to ground in CKT 139 and replace the ABS IGN Fuse. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
18 | Repair the open or high resistance in CKT 450. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
19 | Repair the open or high resistance in CKT 1640. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
20 | Repair the open or high resistance in CKT 139. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
21 | Repair the open or high resistance in CKT 1807. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
22 | Repair the short to ground in CKT 1807. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
23 | Replace the terminals or the connectors that exhibit the following conditions:

• | Poor terminal contact

• | Terminal corrosion

• | Damaged terminals

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

24 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --