Trouble Code Does Not Appear

DIAGNOSIS: 

• Diagnosis circuit is open.

TROUBLE SYMPTOM: 

• The ABS warning light turns on or off normally but the start code cannot be read out in the diagnostic mode.

WIRING DIAGRAM: 

Fig 1: Wiring Diagram

1. 7C1: CHECK DIAGNOSIS TERMINAL. 

   Measure resistance between diagnosis terminals (B81) and chassis ground.

   Terminals 

   1. Diagnosis terminal (A) - Chassis ground: 
   2. Diagnosis terminal (B) - Chassis ground: 
   Fig 2: Measuring Resistance Between Diagnosis Terminals (B81) & Chassis Ground

   

   CHECK: Is the resistance less than 0.5 ohm? 

   1. YES:  Go to step 7C2. 
   2. NO:  Repair diagnosis terminal harness.
2. 7C2: CHECK DIAGNOSIS LINE. 
   1. Turn ignition switch to OFF.
   2. Connect diagnosis terminal (B81) to diagnosis connector (B82) No. 6.
   3. Disconnect connector from ABSCM & H/U.
   4. Measure resistance between ABSCM & H/U connector and chassis ground.

   Connector & terminal 

   1. (F49) No. 4 - Chassis ground: 
   Fig 3: Measuring Resistance Between ABSCM & H/U Connector & Chassis Ground

   

   CHECK: Is the resistance less than 0.5 ohm? 

   1. YES:  Go to step 7C3. 
   2. NO:  Repair harness connector between ABSCM & H/U and diagnosis connector.
3. 7C3: CHECK POOR CONTACT IN ABSCM & H/U CONNECTOR. 

   CHECK: Is there poor contact in ABSCM & H/U connector? 

   1. YES:  Repair connector.
   2. NO:  Replace ABSCM & H/U, see ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT (ABSCM & H/U)  .