Component Tests and General Diagnostics
DIAGNOSISTo ensure that the trouble diagnosis is done accurately and smoothly, observe "Precautions in Diagnosing Troubles" and follow "ABS Diagnostic Flow Table".
PRECAUTION IN DIAGNOSING TROUBLES
^ If the vehicle was operated in any of the following ways, ABS warning light may light momentarily but this does not indicate anything abnormal in ABS.
- The vehicle was driven with parking brake pulled.
- The vehicle was driven with brake dragging.
- The vehicle was stuck in mud, sand, etc.
- Wheel spin occurred while driving.
- Wheel(s) was rotated while the vehicle was jacked up.
^ Be sure to use the trouble diagnosis procedure as described in the flow table.
Failure to follow the flow chart may result in incorrect diagnosis. (Some other diagnostic trouble code may be stored by mistake in the memory of ABS control module during inspection.)
ABS DIAGNOSTIC FLOW TABLE
Refer to the following for the details of each step.
1. CUSTOMER COMPLAINT ANALYSIS
Record details of the problem (failure, complaint) and how it occurred as described by the customer. For this purpose, use of such a questionnaire form as shown below will facilitate collecting information to the point required for proper analysis and diagnosis.
CUSTOMER QUESTIONNAIRE (EXAMPLE)
2. PROBLEM SYMPTOM CONFIRMATION
Check if what the customer claimed in Step 1 is actually found in the vehicle and if that symptom is found, whether it is identified as a failure. (This step should be shared with the customer if possible.) When ABS warning lamp is not operated correctly, proceed to "Diagnostic Flow Table-A, B or C".
3. DIAGNOSTIC TROUBLE CODE (DTC) CHECK, RECORD AND CLEARANCE
Perform "Diagnostic Trouble Code Check", record it and then clear it referring to "Diagnostic Trouble Code Clearance".
If the malfunction DTC which was once displayed and then cleared cannot be detected (indicated) again when the ignition switch is turned ON position, attempt to diagnose the trouble based on the DTC recorded in this step may mislead the diagnosis or make diagnosing difficult. Proceed to Step 4 to check ABS control module for proper self-diagnosis function.
If the malfunction DTC, which was once displayed and then cleared can be detected (indicated) again when ignition switch is turned ON position, proceed to Step 5.
4. DRIVING TEST
Test drive the vehicle at 40 km/h (25.0 mile/h) for more than a minute and check if any trouble symptom (such as abnormal lighting of ABS warning lamp) exists.
If the malfunction DTC is confirmed again at ignition switch is ON position, driving test as described in above is not necessary. Proceed to Step 5.
5. DIAGNOSTIC TROUBLE CODE CHECK
Recheck diagnostic trouble code referring to "DTC CHECK".
6. DIAGNOSTIC TROUBLE CODE FLOW TABLE
According to Diagnostic flow table for the diagnostic trouble code confirmed in Step 5, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, ABS control module or other part and repair or replace faulty parts.
7. "DIAGNOSIS"
Check the parts or system suspected as a possible cause and based on symptoms appearing on the vehicle (symptoms obtained through Steps 1, 2 and 4) and repair or replace faulty parts, if any.
8. CHECK FOR INTERMITTENT PROBLEM
Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.) and related circuit of trouble code recorded in Step 3.
9. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the ABS is free from any abnormal conditions. If what has been repaired is related to the malfunction DTC, clear the DTC once and perform test driving and confirm that a normal code is indicated.