The key to successful troubleshooting is doing everything systematically and in order until all possibilities are eliminated and the real problem is found. Honda uses the term "problem" for a malfunction, and system diagnosis is done by tracking down problem "codes" which describe alleged malfunctions (problems) in the system. Special Honda factory tools may be needed for certain procedures involving the anti-lock brake system. Read the procedures thoroughly to determine whether you are prepared to undertake the repairs involved.
Vehicles with ALB/ABS have an electronic "problem" memory and an indicator light on the instrument panel. When the engine is first started, the light will go on to indicate the system is pressurizing and performing a self-diagnostic check. After the system is at full pressure, the light will go out. If it remains lit, there is a problem detected in the system.
The fault(s) in the system must be verified by simulated operations on the various components of the ALB/ABS system which are performed by the Honda ALB/ABS Checker, or equivalent. If this diagnostic equipment is not available, most of the system can still be tested with a digital multimeter (volt/ohmmeter in one). Service for the system is quite limited. Most components cannot be repaired, only replaced.
Before diagnosing an apparent ALB/ABS problem, make absolutely certain that the normal braking system is in correct working order. Many common brake problems (dragging parking brake, seepage, etc.) will affect the ALB/ABS system. A visual check of specific system components may reveal problems that simulate an apparent ALB/ABS malfunction. Performing this inspection may reveal a simple failure, thus eliminating extended diagnostic time.
- Inspect the tire pressures; they must be approximately equal for the system to operate correctly.
- Inspect the wheels and tires on the vehicle. They must be of the same size and type to generate accurate speed signals.
- Inspect the brake fluid level in the reservoir.
- Inspect brake lines, hoses, master cylinder assembly and brake calipers for leakage.
- Visually check brake lines and hoses for excessive wear, heat damage, punctures, contact with other parts, missing clips or holders, blockage or crimping.
- Check the calipers for rust or corrosion. Check for proper sliding action if applicable.
- Check the calipers for freedom of motion during application and release.
- Inspect the speed sensors for proper mounting and connections (see section later in this guide for the procedure).
- Inspect the gear pulsers for broken teeth or poor mounting (see section later in this guide for the procedure).
- Certain driver induced problems, such as not releasing the parking brake fully, spinning the wheels under acceleration, sliding due to excessive cornering speed or driving on extremely rough surfaces may fool the system and trigger the dash warning light. These induced problems are not system failures; they are examples of vehicle performance outside the parameters of the control unit.
- Many system shutdowns are due to loss of sensor signals to or from the controller. The most common cause is not a failed sensor, but a loose, corroded or dirty connector. Check harness and component connectors carefully.
- Check for correct battery voltage and inspect the condition of all ALB/ABS fuses.
Reading Problem Codes
See Figures 1 and 2
If the ALB/ABS indicator light comes on and remains on while the engine is running, there may or may not be a (real) problem with the system. Before assuming there is, go through the following steps to determine if there was a false alarm, or to determine exactly which problem code should be checked.
- Turn off the engine and then turn the ignition key back to the ON position to see whether the indicator light comes on as it should. Then restart the engine to confirm whether the light will remain on or go off as normal.
- If the light comes on with the ignition on, and goes off with the engine running, there is no problem.
If the indicator light on the dashboard does not come on at all, stop here and refer to the following section "ABS Indicator Light."
- If the ALB/ABS indicator light remains on with the engine running, thus confirming that a problem has been detected, stop the engine. Disconnect the service check connector from the connector cover under the glove box and connect the two terminals with a jumper wire.
- Turn the ignition ON without starting the engine to determine the problem. The ALB/ABS control unit will communicate by a series of blinks through the ALB/ABS indicator light which problem code(s) must be checked.
- To understand the blinks, record the blinking frequency of the ALB/ABS indicator light and compare it to the Problem Code Chart following. The blinking frequency will indicate the problem code. If you miscount the blinking frequency, or want to make sure, turn OFF the ignition and then turn it ON again to repeat the cycle.
- Once the problem code(s) have been determined by use of the Symptom-to-System Chart following, use a digital multimeter and the appropriate flowcharts (provided after the code chart) to test the system. Start at the beginning and work all the way towards the end before removing any components.
- After repairs, make sure the warning light on the instrument panel operates properly. It should light when the ignition is first turned ON , then go out after the vehicle starts moving. If not, the system is still not repaired.
See Figure 3
The ALB/ABS indicator light should always come on when the ignition key is turned ON , and then go out when the car is started. If the light fails to operate and the car's electrical system is energized, check the following items. If they are OK, check the control unit connectors. If not loose or disconnected, substitute a known-good control unit (if possible) and recheck:
The testing of the ALB/ABS system may require the Bleeder T-Wrench, Honda part No. 07HAA-SG00101 and a digital multimeter. If you intend to service and maintain your ALB/ABS system, investment in these tools may be necessary.
After a repair is completed, the ALB/ABS B2 (15A) fuse must be disconnected for a minimum of three seconds to erase the control unit's memory. Then turn the ignition key ON and recheck. The memory is erased if the connector is disconnected from the control unit or the control unit is removed from the body.
DIAGNOSTIC FLOW CHARTS
See Figures 4 through 23
The accompanying charts should be used along with the information in this section to help troubleshoot system problem codes.