How To Troubleshoot The ABS
How to Troubleshoot the ABS
System Indicator
This system has three indicators:
- ABS indicator (A)
- Brake system indicator (red) (B)
- Brake system indicator (amber) (C)
When the system is OK, each indicator comes on for about 2 seconds after turning the ignition switch to ON (II), then goes off.
When the system detects a problem, a DTC is set and, depending upon the failure, the ABS modulator-control unit determines which indicator(s) are turned on. If the problem goes away (system returns to normal), the indicator(s) are controlled in the following way depending upon the DTC that was set:
- The indicator(s) will come on and stay on when the ignition switch is ON (II).
- The indicator(s) automatically go off.
- The indicator(s) go off after the vehicle is driven.
ABS Indicator
The ABS indicator comes on when the ABS function is lost. The brakes still work like a conventional system.
Brake System Indicator (Red)
The brake system indicator (red) comes on when the electronic brake distribution EBD function is lost, the parking brake is applied, and/or the brake fluid level is low.
NOTE: If two or more wheel speed sensors fail, the brake system indicator (red) will come on.
Brake System Indicator (Amber)
The brake system indicator (amber) comes on when the creep aid system CAS function is lost.
ABS Indicator, and Brake system Indicator (Amber) go off
Each indicator will go off after a problem goes away, but the timing which the ABS modulator-control unit turns off the indicators varies between DTCs.
- DTC 61, 62:The indicators go off automatically when the system returns to normal.
- DTC 11, 13, 15, 17, 31-38, 54, 64, 66, 68, 81, 83, 86, 105, 121-124:The indicators stay on until the ignition switch is turned to LOCK (0) whether or not the system returns to normal.
- DTC 12, 14, 16, 18, 21-24, 51, 52:The indicators stay on until the vehicle is driven after the system returns to normal.
Diagnostic Trouble Code (DTC)
- The memory can hold all 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 occur.
- The DTCs are memorized in the EEPROM in the ABS modulator-control unit. Therefore, the memorized DTCs cannot be erased by disconnecting the battery. Do the specified procedures to clear the DTCs.
Self-diagnosis
- Self-diagnosis can be classified into two categories:
- Initial diagnosis: Done right after the ignition switch is turned to ON (II) and until the ABS indicator, and Brake system indicator (amber) goes off.
- Regular diagnosis: Done right after the initial diagnosis until the ignition switch is turned to LOCK (0).
- When the system detects a problem, the ABS modulator-control unit shifts to fail-safe mode.
Kickback
The pump motor operates when the ABS modulator-control unit 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 modulator-control unit is functioning.
- The ABS modulator-control unit checks the pump motor operation during the first acceleration after the vehicle starts driving.
Brake Fluid Replacement/Air Bleeding
Brake fluid replacement and air bleeding procedures are identical to the procedures used on vehicles without the ABS Service and Repair.
How to Troubleshoot DTCs
The troubleshooting procedures assume that the cause of the problem is still present and the ABS indicator and the brake system indicator (amber) are still on. Following a troubleshooting procedure for a DTC that has been cleared but does not reset can result in incorrect diagnosis.
1. Question the customer about the conditions when the problem occurred, and try to reproduce the same conditions for troubleshooting. Find out when the ABS indicator and the brake system indicator (amber) came on, such as during activation, after activation, when the vehicle was traveling at a certain speed, etc. If necessary, have the customer demonstrate the concern.
2. When the ABS indicator and the brake system indicator (amber) do not come on during the test-drive, but troubleshooting is done based on the DTC, check for loose connectors, poor contact of the terminals, etc. before you start troubleshooting.
3. After troubleshooting, or the repairs are done, clear the DTCs, and test-drive the vehicle under the same conditions that originally set the DTCs. Make sure the ABS indicator and the brake system indicator (amber) does not come on.
Intermittent Failures
The term "intermittent failure" means a system may have had a failure, but it checks OK now. If you cannot reproduce the condition, check for loose connections and terminals. Also check ground and power connections related to the circuit that you are troubleshooting.
How to Use the HDS (Honda Diagnostic System)
NOTE: Make sure the 12 volt battery is in good condition and fully charged.
1. If the system indicators stay on, connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the ABS modulator-control unit. If it does not, go to the DLC circuit troubleshooting DLC Circuit Troubleshooting (PGM-FI System).
4. Check the diagnostic trouble code (DTC) for all systems, and make a note of them. Troubleshoot the powertrain DTCs first. Then refer to the indicated DTC's troubleshooting, and do the appropriate troubleshooting procedure.
NOTE:
- The HDS communication will be stopped when the vehicle speed is at 31 mph (50 km/h) or more.
- The HDS read the DTC, the current data, and other system data.
- For specific operations, refer to the Help menu that came with the HDS.
How to Retrieve DTCs
1. With the ignition switch in LOCK (0), connect the HDS to the data link connector (DLC) under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the ABS modulator-control unit. If it does not, go to the DLC circuit troubleshooting DLC Circuit Troubleshooting (PGM-FI System).
4. Follow the prompts on the HDS to display the DTC(s) on the screen. After determining the DTC, refer to the DTC troubleshooting. Do all systems DTC check, and troubleshoot any powertrain DTCs first.
5. Turn the ignition switch to LOCK (0).
How to Clear DTCs
1. With the ignition switch in LOCK (0), connect the HDS to the data link connector (DLC) under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the ABS modulator-control unit. If it does not, go to the DLC circuit troubleshooting DLC Circuit Troubleshooting (PGM-FI System).
4. Clear the DTC(s) by following the screen prompts on the HDS.
5. Turn the ignition switch to LOCK (0).