DTC Description
DTC DETECTION LOGIC
DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condit |
P0078 | EX V/T ACT/CIRC-B1 (Exhaust valve control solenoid circuit bank 1) | An improper voltage is sent to the ECM through exhaust valve timing control solenoid valve. |
POSSIBLE CAUSE
FAIL-SAFE
Device fix mode
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO2.
2.PERFORM DTC CONFIRMATION PROCEDURE
Is 1st trip DTC detected? YES >> Proceed to EC-195, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK EXHAUST VALVE TIMING CONTROL SOLENOID VALVE POWER SUPPLY
Is the inspection result normal? YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK EXHAUST VALVE TIMING CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
Is the inspection result normal? YES >> Perform the trouble diagnosis for power supply circuit.
NO >> Repair or replace error-detected parts.
3.CHECK EXHAUST VALVE TIMING CONTROL SOLENOID VALVE GROUND CIRCUIT
Is the inspection result normal? YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK EXHAUST VALVE TIMING CONTROL SOLENOID VALVE
Check the exhaust valve timing control solenoid valve. Refer to EC-183, "Component Inspection".
Is the inspection result normal? YES >> GO TO 5.
NO >> Replace exhaust valve timing control solenoid valve.
5.CHECK INTERMITTENT INCIDENT
Refer to GI-41, "Intermittent Incident".
>> INSPECTION END
Component Inspection
1.CHECK EXHAUST VALVE TIMING CONTROL SOLENOID VALVE-1
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace exhaust valve timing control solenoid valve. Refer to EM-44, "Exploded View".
2.CHECK EXHAUST VALVE TIMING CONTROL SOLENOID VALVE-2
CAUTION: Do not apply 12 V DC continuously for 5 seconds or more.
Doing so may result in damage to the coil in exhaust valve timing control solenoid valve.
NOTE: Always replace O-ring when exhaust valve timing control solenoid valve is removed.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace exhaust valve timing control solenoid valve. Refer to EM-44, "Exploded View".
Overdrive control switch
Component Function Check
1.CHECK O/D OFF INDICATOR LAMP FUNCTION
Check O/D OFF indicator lamp turns ON for approx. 2 seconds when ignition
switch turns ON.
Is the inspection results normal?
YES >> GO TO 2.
NO >> Go to TM-181, "Diagnosis Procedure".
2.CHECK OVERDRIVE ...
C1164, C1165 CV system
DTC Logic
DTC Logic
DTC
Display Item
Malfunction detected condition
Possible causes
C1164
CV 1
When a malfunction is detected in cut valve 1.
Harness or connector
ABS actuator and electric unit
(control unit)
Fusible link
  ...
Diagnosis and repair workflow
Work Flow
OVERALL SEQUENCE
DETAILED FLOW
1. OBTAIN INFORMATION ABOUT SYMPTOM
Interview the customer to obtain as much information as possible about the
conditions and environment under
which the malfunction occurred.
>> GO TO 2.
2. CONFIRM THE SYMPTOM
Check the malfunction on the ...