DIAGNOSIS SYSTEM

1. DIAGNOSIS

If the skid control ECU detects a malfunction, the ABS warning and the brake warning lights will come on to warn the driver.
The table below indicates which lights will come on when there is a malfunction in a particular function.

Item / Trouble Area ABS EBD

ABS warning light ○ ○

Brake warning light - ○

○: Light ON
- : Light OFF
- The DTCs are simultaneously stored in the memory. The DTCs can be read by connecting the SST between terminals TC and CG of the DLC3 and observing the blinking pattern of the ABS warning light, or by connecting the intelligent tester.
- This system has a Test Mode (signal check) function (See TEST MODE PROCEDURE).
  The DTC can be read by connecting the intelligent tester and observing the blinking pattern of the ABS warning light.

2. WARNING LIGHT INITIAL CHECK

Release the parking brake.

When releasing the parking brake, set chocks to hold the vehicle for safety.

When the parking brake is applied, the level of the brake fluid is low or the vacuum is low, the brake warning light comes on.
When the ignition switch is turned to the ON position, check that the ABS and brake warning lights come on for approximately 3 seconds.

If the warning light and indicator light check result is not normal, proceed to troubleshooting for the ABS and brake warning light circuits.
If the indicator remains on, proceed to troubleshooting for the light circuit below.

Trouble Area

ABS warning light circuit (Remains on)

Brake warning light circuit (Remains on)

3. SYMPTOM SIMULATION

The most difficult case in troubleshooting is when no symptoms occur. In such cases, a thorough customer problem analysis must be carried out. Then the same or similar conditions and environment in which the problem occurred in the customer's vehicle should be reproduced. No matter how experienced or skilled a technician may be, if he proceeds to troubleshooting without confirming the problem symptoms, he will likely overlook something important and make a wrong guess at some points in the repair operation. This leads to a standstill in troubleshooting.

Vibration method: When vibration seems to be the major cause.

Perform the simulation method only during the primary check period (for approximately 6 seconds after the ignition switch is turned to the ON position).
1. Slightly vibrate the part of the sensor considered to be the problem cause with your fingers and check whether the malfunction occurs.
2. Slightly shake the connector vertically and horizontally.
  
  Shaking the relays too strongly may result in open relays.
3. Slightly shake the wire harness vertically and horizontally. The connector joint and fulcrum of the vibration are the major areas to be checked thoroughly.

Item / Trouble Area	ABS	EBD
ABS warning light	○	○
Brake warning light	-	○