ASE L1 Domain 6: I/M Failure Diagnosis Welcome to your ASE L1 Domain 6: I/M Failure Diagnosis 1. ASE L1: I/M Failure Diagnosis When a vehicle fails an I/M 240 test for NOx at cruise but passes at idle, which of the following is the MOST likely cause? A. A malfunctioning catalytic converter. B. A defective EGR valve. C. A faulty oxygen sensor. D. An incorrect ignition timing. None 2. ASE L1: I/M Failure Diagnosis A vehicle consistently fails the I/M readiness test due to the EVAP monitor not setting. The most appropriate initial diagnostic step would be to: A. Check for a loose gas cap. B. Perform a smoke test for system leaks. C. Verify the vehicle's driving conditions history. D. Replace the EVAP canister purge valve. None 3. ASE L1: I/M Failure Diagnosis In a vehicle that fails the I/M NOx test, the presence of a lower than normal MAP sensor voltage reading would suggest: A. A leak in the intake manifold. B. A malfunctioning EGR valve. C. An over-reporting oxygen sensor. D. Incorrect fuel pressure. None 4. ASE L1: I/M Failure Diagnosis A vehicle that fails an I/M test for CO and HC but passes for NOx might have: A. An excessively rich fuel mixture. B. A faulty catalytic converter. C. A lean air-fuel mixture. D. A malfunctioning EGR system. None 5. ASE L1: I/M Failure Diagnosis If a vehicle fails the I/M test with high HC readings at idle but passes at higher RPMs, the MOST likely cause is: A. A misadjusted idle mixture. B. A faulty ignition coil. C. An incorrect valve timing. D. A clogged air filter. None 6. ASE L1: I/M Failure Diagnosis Upon failing an I/M test due to a high CO level at high RPM, what should be the first parameter a technician should check? A. Engine load data. B. Exhaust gas recirculation data. C. Oxygen sensor activity. D. Air intake temperature. None 7. ASE L1: I/M Failure Diagnosis A vehicle repeatedly fails the OBD-II I/M readiness test due to the catalyst monitor not setting. This could be a result of: A. A shorted coolant temperature sensor. B. Infrequent vehicle use. C. A damaged exhaust manifold. D. A depleted battery. None 8. ASE L1: I/M Failure Diagnosis A vehicle fails the I/M test with a trouble code indicating "System Too Lean." What should be inspected first? A. Fuel pump output. B. MAF sensor operation. C. Throttle position sensor. D. Aftermarket air intake modifications. None 9. ASE L1: I/M Failure Diagnosis During an I/M test, a vehicle displays a trouble code for insufficient EGR flow. Which diagnostic test should be performed first? A. Inspection of the EGR valve and passage for clogging. B. Measurement of the intake manifold vacuum. C. Backpressure testing of the exhaust system. D. Checking the operation of the EGR temperature sensor. None 10. ASE L1: I/M Failure Diagnosis When a vehicle passes all emissions tests but fails for an illuminated Check Engine Light, the technician should FIRST: A. Reset the ECU to clear the codes. B. Perform a full vehicle scan for diagnostic trouble codes. C. Check the instrument cluster for proper operation. D. Inspect the wiring to the Check Engine Light. None 1 out of 10 Time is Up! Time's up
