For 1990-2009 cars

## DTC C0550 North America

### Circuit Description

The antilock brake system (ABS) control module performs various diagnostic checks on itself. If it finds a problem, it sets DTC C0550.

This procedure checks whether there is a poor ground connection for the electronic brake control module (EBCM).

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0550 Electronic Control Unit (ECU) Performance

### Conditions for Running the DTC

• | Vehicle speed is greater than 6 km/h (4 mph) with the brake pedal not applied

| or

• | Vehicle speed is greater than 15 km/h (9 mph) and the brake pedal is actuated.

### Conditions for Setting the DTC

• | A connector terminal is corroded.

• | The EBCM is malfunctioning.

### Action Taken When the DTC Sets

The ABS is disabled, and the ABS warning lamp is turned ON. The electronic brake force distribution (EBD) is disabled. If the failure is intermittent, the control module will enable the system at the next ignition cycle and will store a history DTC C0550.

### Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

### Diagnostic Aids

It is very important to perform a thorough inspection of the wiring and the connectors. Failure to inspect the wiring and the connectors carefully and completely may result in misdiagnosis, causing part replacement with the reappearance of the malfunction.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step begins the testing for a poor voltage or ground connection.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Are DTCs other than C0550 set? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | Go to Step 3
3 | Clear all DTCs and road test the vehicle. Does DTC C0550 set again? | -- | Go to Step 5 | Go to Step 4
4 |

1. Inspect all wiring harness connectors and terminals, especially those at the electronic brake control module (EBCM), for any condition that could cause an intermittent.
2. Repair any problems found.

Did you find and correct the condition?

--

Go to Step 11

--

5 |

1. Turn the ignition switch to OFF.
2. Disconnect the EBCM connector J1.
3. Turn the ignition switch to ON.
4. Measure the voltage between ground and terminals 20, 14, and 1 of the EBCM harness connector J1.

Does the voltage measure within the specified range?

11-14 V

Go to Step 7

Go to Step 6

6 |

1. Inspect the voltage supply and the ground connections to the EBCM.
2. Repair any open or high resistance found.

Did you find and correct the condition?

--

Go to Step 11

--

7 | Inspect the EBCM connector J1 for any ineffective terminals. Are there any ineffective terminals? | -- | Go to Step 8 | Go to Step 9
8 | Repair any connector problem found. Did you complete the repair? | -- | Go to Step 11 | --
9 | Clear all DTCs and road test the vehicle. Does DTC 0550 set again? | -- | Go to Step 10 | System OK
10 | Replace the EBCM. Did you complete the replacement? | -- | Go to Step 11 | --
11 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK

## DTC C0550 Except North America

### Circuit Description

The antilock brake system (ABS) control module performs various diagnostic checks on itself. If it finds a problem, it sets DTC C0550.

This procedure checks whether there is a poor ground connection for the electronic brake control module (EBCM).

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0550 Electronic Control Unit (ECU) Performance

### Conditions for Running the DTC

• | Vehicle speed is greater than 6 km/h (4 mph) with the brake pedal not applied

| or

• | Vehicle speed is greater than 15 km/h (9 mph) and the brake pedal is actuated.

### Conditions for Setting the DTC

• | A connector terminal is corroded.

• | The EBCM is malfunctioning.

### Action Taken When the DTC Sets

The ABS is disabled, and the ABS warning lamp is turned ON. The electronic brake force distribution (EBD) is disabled. If the failure is intermittent, the control module will enable the system at the next ignition cycle and will store a history DTC C0550.

### Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

### Diagnostic Aids

It is very important to perform a thorough inspection of the wiring and the connectors. Failure to inspect the wiring and the connectors carefully and completely may result in misdiagnosis, causing part replacement with the reappearance of the malfunction.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step begins the testing for a poor voltage or ground connection.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Are DTCs other than C0550 set? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | Go to Step 3
3 | Clear all DTCs and road test the vehicle. Does DTC C0550 set again? | -- | Go to Step 5 | Go to Step 4
4 |

1. Inspect all wiring harness connectors and terminals, especially those at the electronic brake control module (EBCM), for any condition that could cause an intermittent.
2. Repair any problems found.

Did you find and correct the condition?

--

Go to Step 11

--

5 |

1. Turn the ignition switch to OFF.
2. Disconnect the EBCM connector J1.
3. Turn the ignition switch to ON.
4. Measure the voltage between ground and terminals 32, 4, and 1 of the EBCM harness connector J1.

Does the voltage measure within the specified range?

11-14 V

Go to Step 7

Go to Step 6

6 |

1. Inspect the voltage supply and the ground connections to the EBCM.
2. Repair any open or high resistance found.

Did you find and correct the condition?

--

Go to Step 11

--

7 | Inspect the EBCM connector J1 for any ineffective terminals. Are there any ineffective terminals? | -- | Go to Step 8 | Go to Step 9
8 | Repair any connector problem found. Did you complete the repair? | -- | Go to Step 11 | --
9 | Clear all DTCs and road test the vehicle. Does DTC 0550 set again? | -- | Go to Step 10 | System OK
10 | Replace the EBCM. Did you complete the replacement? | -- | Go to Step 11 | --
11 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK