How to Troubleshoot the ABS

ABS Indicator


  • If the system is OK, the ABS indicator goes off 2 seconds after turning the ignition switch ON (II) without starting the engine, and then comes on again and goes off 2 seconds later after starting the engine. This occurs because the ABS control unit is turned on by the IG1 power source.
  • The ABS indicator comes on when the ABS control unit detects a problem in the system. However, even though the system is operating properly, the indicator will come on under these conditions:
    • Only the drive wheels rotate
    • One drive wheel is stuck
    • The vehicle goes into a spin
    • The ABS continues to operate for a long time.
    • The vehicle is subjected to an electrical signal disturbance

To determine the actual cause of the problem, question the customer about the problem, taking the above conditions into consideration.

  • When a problem is detected and the ABS indicator comes on, there are cases when the indicator stays on until the ignition switch is turned OFF, and cases when the indicator goes off automatically when the system returns to normal.
    • DTC 61, 62:
      The ABS indicator goes off automatically when the system returns to normal.
    • DTC 11, 13, 15, 17, 31, 32, 33, 34, 35, 36, 37, 38, 54, or 81:
      The ABS indicator stays on until the ignition switch is turned OFF whether or not the system returns to normal.
    • DTC 12, 14, 16, 18, 21, 22, 23, 24, 51, 52, or 53:
      The ABS indicator goes off when the vehicle is driven again and the system is OK after the ignition switch is turned from OFF to ON (II).

Diagnostic Trouble Code (DTC)


  • The memory can hold three DTCs. However, when the same DTC is detected more than once, the more recent DTC is written over the earlier one.
    Therefore, when the same problem is detected repeatedly, it is memorized as a single DTC.
  • The DTCs are indicated in the order they occurred, beginning with the most recent.
  • The DTCs are memorized in the EEPROM (non-volatile memory). Therefore, the memorized DTCs are not cleared when the battery is disconnected, the ignition switch is turned off, or the system returns to normal. Perform the specified procedures to clear the DTCs.

Self-diagnosis


  • Self-diagnosis can be classified into two categories:
    • Initial diagnosis:
      Done right after the engine starts and until the ABS indicator goes off
    • Regular diagnosis:
      Done right after the initial diagnosis until the ignition switch is turned OFF
  • When a problem is detected by self-diagnosis, the system does the following:
    • Turns the ABS indicator on
    • Memorizes the DTC
    • Stops ABS control

Kickback


The pump motor operates when the ABS is functioning, and the fluid in the reservoir is forced out to the master cylinder, causing kickback at the brake pedal.

Pump Motor


  • The pump motor operates when the ABS is functioning.
  • The ABS control unit checks the pump motor operation when the vehicle is started the first time after the ignition switch is turned ON (II). You may hear the motor operate at this time, but it is normal.

How to Troubleshoot ABS DTCs


The troubleshooting flowchart procedures assume that the cause of the problem is still present and the ABS indicator is still on. Following the flowchart when the ABS indicator does not come on can result in incorrect diagnosis.
The connector illustrations show the female terminal connectors with a single outline and the male terminal connectors with a double outline.

1.Question the customer about the conditions when the problem occured, and try to reproduce the same conditions for troubleshooting. Find out when the ABS indicator came on, such as during ABS control, after ABS control, when the vehicle was at a certain speed, etc.

2.When the ABS indicator does not come on during the test-drive, but troubleshooting is done based on the DTC, check for loose connectors, poor terminal contact, etc., before you start troubleshooting.

3.After troubleshooting, clear the DTC and test-drive the vehicle. Be sure the ABS indicator does not come on.

How to Retrieve ABS DTCs


Honda PGM Tester Method:

1.With the ignition switch OFF, connect the Honda PGM Tester (A) to the 16P Data Link Connector (DLC) (B) right side of the under-dash fuse/relay box.

 

2.Turn the ignition switch ON (II), and follow the prompts on the PGM Tester to display the DTC (s) on the screen. After determining the DTC, refer to the DTC Troubleshooting Index.

NOTE: See the Honda PGM Tester user's manual for specific instructions.

SCS Short Connector Method (EU Model):


1.With the ignition switch OFF, connect the SCS short connector (A) to the service check connector (2P) (B) right side of the under-dash fuse/relay box.

 

2.Turn the ignition switch ON (II) without pressing the brake pedal.

NOTE: If you press the brake pedal when turning the ignition switch ON (II), the system shifts to the DTC clearing mode.

3.The blinking frequency indicates the DTC. DTCs are indicated by a series of long and short blinks. One long blink equals 10 short blinks. Add the long and short blinks together to determine the DTC. After determining the DTC, refer to the DTC Troubleshooting Index.

NOTE:


The system will not indicate the DTC unless these conditions are met:

  • The ignition switch is turned ON (II).
  • The SCS circuit is shorted to body ground before the ignition switch is turned ON (II).

 

4.Turn the ignition switch OFF.

5.Disconnect the SCS short connector from the service check connector.

DLC Pin Box Method (Except EU Model):

1.With the ignition switch OFF, connect the DLC pin box (A) to the 16P Data Link Connector (DLC) (B) right side of the under-dash fuse/relay box..

 

2.Insert the plugs of the jumper wire (C) to No. 4 and No. 9 plug holes of the DLC terminal box, then push the switch.

3.Turn the ignition switch ON (II) without pressing the brake pedal.

NOTE: If you press the brake pedal when turning the ignition switch ON (II), the system shifts to the DTC clearing mode.

4.The blinking frequency indicates the DTC. DTCs are indicated by a series of long and short blinks. One long blink equals 10 short blinks. Add the long and short blinks together to determine the DTC. After determining the DTC, refer to the DTC Troubleshooting Index.

NOTE:


The system will not indicate the DTC unless these conditions are met:

  • The brake pedal is not pressed.
  • The ignition switch is turned ON (II).
  • The SCS circuit is shorted to body ground before the ignition switch is turned ON (II).

 


5.Turn the ignition switch OFF.

6.Disconnect the DLC pin box from the DLC.

How to Clear ABS DTCs


Honda PGM Tester Method:

1.With the ignition switch OFF, connect the Honda PGM Tester (A) to the 16P Data Link Connector (DLC) (B) under the driver's side of the dashboard.

 

2.Turn the ignition switch ON (II), and clear the DTC(s) by following the screen prompts on the PGM Tester.

NOTE: See the Honda PGM Tester user's manual for specific instructions.

SCS Short Connector Method (Except EU Model):

1.With the ignition switch OFF, connect the SCS short connector (A) to the service check connector (2P) (B) right side of the under-dash fuse/relay box.

 

2.Press the brake pedal.

3.Turn the ignition switch ON (II) while continuing to press the brake pedal.

4.After the ABS indicator goes off, release the brake pedal.

5.After the ABS indicator comes on, press the brake pedal again.

6.After the ABS indicator goes off, release the brake pedal.

You cannot clear the DTC unless these conditons are met:

  • The vehicle speed is 6 mph (10 km/h) or less.
  • The SCS circuit is shorted to body ground before the ignition switch is turned ON (II).
  • The brake pedal is press before the ignition switch is turned ON (II).

7.After a few seconds, the ABS indicator blinks twice and the DTC is cleared. If the indicator does not blink twice, repeat steps 1 thru 6. If the ABS indicator stays on after it blinks twice, check the DTC, because a problem was detected during initial diagnosis before shifting to DTC clearing mode.

8.Turn the ignition switch OFF.

9.Disconnect the SCS short connector from the service check connector.

DLC pin Box Method (Except EU Model):

1.With the ignition switch OFF, connect the DLC pin box (A) to the 16P Data Link Connector (DLC) (B) right side of the under-dash fuse/relay box.

 

2.Insert the plugs of the jumper wire (C) to No. 4 and No. 9 plug holes of the DLC pin box, then push the switch.

3.Press the brake pedal.

4.Turn the ignition switch ON (II) while continuing to press the brake pedal.

5.After the ABS indicator goes off, release the brake pedal.

6.After the ABS indicator comes on, press the brake pedal again.

7.After the ABS indicator goes off, release the brake pedal.

You cannot clear the DTC unless these conditions are met:

  • The vehicle speed is 6 mph (10 km/h) or less.
  • The SCS circuit is shorted to body ground before the ignition switch is turned ON (II).
  • The brake pedal is pressed before the ignition switch is turned ON (II).

8.After a few seconds, the ABS indicator blinks twice and the DTC is cleared. If the indicator does not blink twice, repeat steps 1 thru 7. If the ABS indicator stays on after it blinks twice, check the DTC, because a problem was detected during initial diagnosis before shifting to DTC clearing mode.

9.Turn the ignition switch OFF.

10.Disconnect the DLC pin box from the DLC.