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Problem Symptoms Table

If a normal code is displayed during the DTC check but the problem still occurs, check the circuits for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting section.

NOTE: When replacing skid control ECU, sensor or etc., turn the ignition switch OFF.
PROBLEM SYMPTOMS

Symptom Suspect Area See Section
ABS does not operate Only when 1. to 4. are all normal and the problem is still occurring, replace the skid control ECU.
  1. Check the DTC reconfirming that the normal code is output.
  2. IG power source circuit
  3. Speed sensor circuit
  4. Check the brake actuator with a LEXUS hand-held tester.

If abnormal, check the hydraulic circuit for leakage (See CHECK FOR FLUID LEAKAGE  ).
  1. PRE-CHECK 
  2. DTC C1241 / 41 IG POWER SOURCE CIRCUIT 
  3. CIRCUIT INSPECTION 
  4. BRAKE ACTUATOR
ABS does not operate efficiently Only when 1. to 4. are all normal and the problem is still occurring, replace the skid control ECU.
  1. Check the DTC reconfirming that the normal code is output.
  2. Speed sensor circuit
  3. Stop light switch circuit
  4. Check the brake actuator with a LEXUS hand-held tester.

If abnormal, check the hydraulic circuit for leakage (See CHECK FOR FLUID LEAKAGE ).
  1. PRE-CHECK 
  2. CIRCUIT INSPECTION 
  3. DTC C1249 / 49 STOP LIGHT SWITCH CIRCUIT 
  4. BRAKE ACTUATOR
ABS warning light abnormal
  1. ABS warning light circuit
  2. Skid control ECU
  1. ABS WARNING LIGHT CIRCUIT 
  2. DTC ALWAYS ON MALFUNCTION IN ECU 
TRAC OFF indicator light abnormal(1) Only when inspection circuits for each problem symptom are all normal and the problem is still occurring, replace the skid control ECU.
  1. TRAC OFF indicator light circuit
  2. TRAC cut switch circuit
  1. TRAC OFF INDICATOR, TRAC CUT SWITCH CIRCUIT 
  2. TRAC OFF INDICATOR, TRAC CUT SWITCH CIRCUIT 
DTC check cannot be done Only when inspection circuits for each problem symptom are all normal and the problem is still occurring, replace the skid control ECU.
  1. ABS warning light circuit
  2. VSC warning light circuit
  3. Tc terminal circuit
  1. ABS WARNING LIGHT CIRCUIT 
  2. DTC ALWAYS ON MALFUNCTION IN ECU VSC WARNING LIGHT CIRCUIT 
  3. TC TERMINAL CIRCUIT 
Speed sensor signal check cannot be done
  1. Ts terminal circuit
  2. Skid control ECU
  1. TS TERMINAL CIRCUIT 
  2. DTC ALWAYS ON MALFUNCTION IN ECU 
VSC does not operate Only when inspection circuits for each problem symptom are all normal and the problem is still occurring, replace the skid control ECU.
  1. Check the DTC, reconfirming that the normal code is output.
  2. IG power source circuit
  3. Check the hydraulic circuit for leakage.
  4. Speed sensor circuit
  5. Deceleration sensor circuit
  6. Yaw rate sensor circuit
  7. Steering angle sensor circuit
  1. PRE-CHECK 
  2. DTC C1241 / 41 IG POWER SOURCE CIRCUIT 
  3. CHECK FOR FLUID LEAKAGE 
  4. CIRCUIT INSPECTION 
  5. DTC C1244 / 44 DECELERATION SENSOR CIRCUIT 
  6. DTC C1233 / 33,01234 / 34 YAW RATE SENSOR CIRCUIT 
  7. DTC C1231 / 31 STEERING ANGLE SENSOR CIRCUIT 
BA does not operate Stop light switch circuit DTC C1249 / 49 STOP LIGHT SWITCH CIRCUIT 
TRAC does not operate Only when inspection circuits for each problem symptom are all normal and the problem is still occurring, replace the skid control ECU.
  1. Check the DTC, reconfirming that the normal code is output.
  2. IG power source circuit
  3. Check the hydraulic circuit for leakage
  4. Speed sensor circuit
  1. PRE-CHECK 
  2. DTC C1241 / 41 IG POWER SOURCE CIRCUIT 
  3. CHECK FOR FLUID LEAKAGE 
  4. CIRCUIT INSPECTION 
SLIP indicator light abnormal SLIP indicator light circuit SLIP INDICATOR LIGHT CIRCUIT 
VSC warning light abnormal Only when inspection circuits for each problem symptom are all normal and the problem is still occurring, replace the skid control ECU.
  1. VSC warning light circuit
  2. Skid control ECU
 DTC ALWAYS ON MALFUNCTION IN ECU VSC WARNING LIGHT CIRCUIT 
(1) : Only for 2WD/tbody>
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