L1 Advanced Engine Performance Tests

ASE L1 Test Preparation

The L1 test includes a series of questions that pertain specifically to a ‘Composite Vehicle.’ This vehicle consists of most of the electronic components and circuits common to all manufacturers’ powertrain control systems. ASE created the ‘Composite Vehicle’ to ensure that the L1 test was fair to all technicians, and not biased toward one particular make of vehicle. After receiving your L1 test registration form and payment, ASE will send you a ‘Composite Vehicle Type 3 Preparation & Reference Booklet.’ This booklet provides the reference material you will need to answer some of the questions on the actual L1 test. This same information will be required to answer some of the questions included in our ASE practice test. For your convenience, there are links below that contain all of the data specific to the L1 composite vehicle type 3, also wiring diagrams and component schematics as well. You’ll need to refer to this material in order to answer some of the practice test questions regarding the composite vehicle.

Main Wiring Diagram Links:

Diagram 1 of 3 (large post view)
Diagram 2 of 3 (large post view)
Diagram 3 of 3 (large post view)
Diagram 1 of 3 (quick view)
Diagram 2 of 3 (quick view)
Diagram 3 of 3 (quick view)

Composite Vehicle Reference Images:

Vehicle Engine Diagram #1 (large post view)
Vehicle Engine Diagram #2 (large post view)
Composite Vehicle Engine Diagram #1 (quick view)
Composite Vehicle Engine Diagram #2 (quick view)

Composite Vehicle Reference Content

L1 Advanced Engine Performance Part 1

Progress:

1. The fuel control system on the composite vehicle remains in open loop at all times. Technician A says that a faulty IAT sensor could be the problem. Technician B says this could be a loose connection at ECM oxygen sensor signal pin terminal. Who is correct?

2. Fuel pressure on a continuous return injection system is within specifications, but leaks down to zero immediately after the pump stops running. What is the most likely cause of this condition?

3. There are two Throttle Position Sensors used by the composite vehicle. Technician A says that the use of two sensors allows for a more accurate measurement of throttle position. Technician B says this is a failsafe in case one sensor fails. Who is correct?

4. All of the following statements regarding the composite vehicle OBD II monitors are true EXCEPT:

5. What test is the most effective when checking a PCV system?

6. A discussion of catalytic converters and their effect on emissions and performance by two Technicians. Technician A says a defective converter will always cause reduced performance. Technician B says a defective catalytic converter can cause high emissions without reducing performance. Who is correct?

7. The TSI test is immediately aborted after 10 seconds in the high-speed mode. Technician A says that the engine could be running too lean. Technician B says that the exhaust system may be leaking. Who is correct?

8. The composite vehicle stalls at idle but restarts. Technician A says an open circuit at pin A of the EGR solenoid could be the problem. Technician B says an open circuit to ECM pin 35 could be the cause. Who is correct?

9. The engine in the composite vehicle will crank but not start. A preliminary diagnosis indicates there is no spark. Technician A says that the ignition module should be replaced. Technician B says that a defective CMP sensor could be the root cause of the problem. Who is correct?

10. What conclusion can be drawn from the I/M 240 inspection report shown above.

11. The composite vehicle fails a two-speed idle test due to excessive carbon monoxide. While the engine is running the PCV valve is removed from the valve cover and CO emissions drop below the maximum allowable limit. Technician A says that the engine may have one or more leaking injectors. Technician B says that this test proves the PCV system is working properly. Who is correct?

12. The composite vehicle won't shift into 3rd gear. Technician A says that a poor connection at TCM terminal 75 could cause this condition. Technician B says that an open circuit on #2 shift solenoid (SS2)could be the cause of the problem. Who is correct?

13. A vehicle has a failed CAN communication. Technician A says a shorted CAN harness could be the problem. Technician B says an open terminating resistor could be the cause. Who is correct?

14. All of the following statements concerning the composite vehicle's fuel system are false EXCEPT:

15. Technician A says that low CO and high 02 readings could be the sign of a lean air/fuel mixture. Technician B says that an engine misfire will result in low CO along with high 02 readings. Who is correct?

16. There is no response when the throttle pedal is depressed on the composite vehicle. Technician A says that broken connections at terminals 18 and 19 will create this condition. Technician B says a broken connection at ECM terminal 49 could be the cause. Who is correct?

[caption id="attachment_1449" align="aligncenter" width="300"]HO2S Waveform ExampleWaveform was captured at 2,000 RPM, Closed loop operation from the HO2S 1/2 sensor.[/caption]

17. The waveform above was captured in closed loop at 2500rpm from the HO2S B1S2 sensor on the composite vehicle. Technician A says that a clogged PCV valve may be generating this pattern. Technician B says that the waveform could be the result of an unintentional ground in the purge flow control circuit. Who is correct?

18. The EFE heater stays energized all the time on an engine with Throttle Body Injection (TBI). Which of the following symptoms would NOT be associated with this condition?

19. All of the following information is typically entered into the computer prior to performing an I/M test EXCEPT:

20. A vehicle with multiport fuel injection stall on deceleration. Technician A says that a contaminated throttle body could be the cause of the problem. Technician B says the problem could be from a faulty TCC solenoid. Who is correct?

21. Two technicians are discussing emission controls and related failure symptoms. Technician A says that a faulty secondary air system can cause backfiring. Technician B says that if the hot air hose is missing on an engine with a thermostatic air cleaner, NOx emissions will be higher than normal. Who is correct?

22. The composite vehicle idles rough and stalls when the transmission is put into gear. Technician A says that the circuit to ECM terminal 35 could have a short to ground. Technician B says that a contaminated throttle body may be the cause of the problem. Who is correct?

23. After a road test the technician reveals that the torque converter clutch is not releasing causing the composite vehicle to stall at a stop. Technician A says the problem could be caused by a broken connection at TCM terminal 78. Technician B says a broken connection at ECM terminal 64 could be the cause. Who is correct?

24. An engine with DI ignition becomes harder to start as ambient temperature drops. Below freezing the engine will not start at all. Technician A says that the coil wire may be bad. Technician B says the problem could be a faulty ignition coil. Who is correct?

25. Oxides of Nitrogen begin to form when combustion temperatures exceed:

Click Submit and your results will be emailed to you, Good Luck!!!

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