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DTC Description
 
 
DTC DETECTION LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2 approaches a specified limit value, the three way catalyst (manifold) malfunction is diagnosed.
DTCM.U.T.-III SE screen terms
(Trouble diagnosis content)
DTC detection condition
P042000TW CATALYST SYS-B1
(Catalyst system efficiency below threshold bank 1)
Diagnosis condition—
Signal (terminal)—
Threshold
  • Three way catalyst (manifold) does not operate properly
  • Three way catalyst (manifold) does not have enough oxygen storage capacity
Diagnosis delay time—
 
 
POSSIBLE CAUSE
  • Three way catalyst (manifold)
  • Exhaust tube
  • Intake air leaks
  • Exhaust air leaks
  • Fuel injector
  • Fuel injector leaks
  • Spark plug
  • Improper ignition timing
 
 
FAIL-SAFE
Not applicable
 
 
DTC Confirmation Procedure
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Turn ignition switch OFF and wait at least 10 seconds.
Will M.U.T.-III SE be used?
.
.
 
2.PERFORM DTC CONFIRMATION PROCEDURE-1
With M.U.T.-III SE
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
  1. Start engine and warm it up to the normal operating temperature.
  2. Turn ignition switch OFF and wait at least 10 seconds.
  3. Turn ignition switch ON.
  4. Turn ignition switch OFF and wait at least 10 seconds.
  5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
  6. Let engine idle for 1 minute.
  7. Select “DATA MONITOR” mode of “ENGINE” using M.U.T.-III SE.
  8. Check that “COOLANT TEMP/S” indicates more than 70°C (158°F).
    If not, warm up engine and go to next step when “COOLANT TEMP/S” indication reaches to 70°C (158°F).
  9. Open engine hood.
  10. Select "SRT STATUS" mode of "ENGINE" using M.U.T.-III SE.
  11. Rev engine up to 2,500 to 3,000 rpm and hold it for 3 consecutive minutes then release the accelerator pedal completely.
  12. Check the indication of “CATALYST”.
Which is displayed on M.U.T.-III SE screen?
: .
: .
 
3.PERFORM DTC CONFIRMATION PROCEDURE-2
  1. Wait 5 seconds at idle.
  2. Rev engine up to 2,500 to 3,000 rpm and maintain it until “INCMP” of “CATALYST” changes to “CMPLT” (It will take approximately 5 minutes).
Does the indication change to “CMPLT”?
.
.
 
4.PERFORM DTC CONFIRMATION PROCEDURE AGAIN
  1. Stop engine and cool it down to less than 70°C (158°F).
  2. Perform DTC confirmation procedure again.
: .
 
5.PERFORM DTC CONFIRMATION PROCEDURE-3
Check 1st trip DTC.
Is 1st trip DTC detected?
Proceed to DTC Diagnosis Procedure
INSPECTION END
 
6.PERFORM COMPONENT FUNCTION CHECK
Without M.U.T.-III SE
  1. Start engine and warm it up to the normal operating temperature.
  2. Turn ignition switch OFF and wait at least 10 seconds.
  3. Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
  4. Let engine idle for 1 minute.
  5. Open engine hood.
  6. Check the voltage between ECM harness connector terminals as per the following condition.
    ECMConditionVoltage (V)
    Connector+–
    Terminal
    F529297Keeping engine speed at 2500 rpm constant under no loadThe voltage fluctuation cycle takes more than 5 seconds.
    • 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
Is the inspection result normal?
-1To check malfunction symptom before repair: Refer to Intermittent IncidentIntermittent Incident.
-2Confirmation after repair: INSPECTION END
Proceed to DTC Diagnosis Procedure.