ECU Diagnostics

Troubleshooting: Blink Codes and Diagnostic Modes

The EC-60™controller contains self-testing diagnostic circuitry that continuously checks for the normal operation of internal components and circuitry, as well as external ABS components and wiring.

Active Diagnostic Trouble Codes

When an erroneous system condition is detected, the EC-60™controller:

1.Illuminates the appropriate indicator lamp(s) and disengages part or all of the ABS and ATC functions. (See page 9.)

2.Places the appropriate trouble code information in the ECU memory.

3.Communicates the appropriate trouble code information over the serial communications diagnostic link as required. Hand-held or PC-based diagnostic tools attach to the vehicle diagnostic connector, typically located on or under the dash (see Figure 9).

Located on	Or	Located Under
Dash Panel		Dash Panel

FIGURE 9 - TYPICAL VEHICLE DIAGNOSTIC CONNECTOR LOCATIONS (J1708/J1587, J1939)

BLINK CODES

Blink codes allow a technician to troubleshoot ABS problems without using a hand-held or PC-based diagnostic tool. Instead, information about the ABS system is communicated by the ECU using the ABS indicator lamp to display sequences of blinks.

Note: The ECU will not enter the diagnostic blink code mode if the wheel speed sensors show that the vehicle is in motion. If the ECU is in the diagnostic blink code mode and then detects vehicle motion, it will exit the blink code mode.

In addition, by operating the blink code switch as described below, one of several diagnostic modes can be entered. See Diagnostic Modes below.

Blink Code Switch Activation

When activating the blink code switch:

1.Wait at least two seconds after “ignition on.” (Except when entering Reconfiguration Mode - see Reconfiguration section on page 10)

2.For the ECU to recognize that the switch is activated “on,” the technician must press for at least 0.1 seconds, but less than 5 seconds. (If the switch is held for more than 5 seconds, the ECU will register a malfunctioning switch.)

3.Pauses between pressing the switch when a sequence is required, (e.g. when changing mode) must not be longer than 2 seconds.

4.After a pause of 3.5 seconds, the ECU will begin responding with output information blinks. See Figure 10 for an example.

Blink Code Timing

The ECU responds with a sequence of blink codes. The overall blink code response from the ECU is called a “message.” Each message includes, depending on the

BENDIX EC-60 ABS-ATC STD-PREM CONTROLLERS manual Troubleshooting Blink Codes and Diagnostic Modes