AND ANSWERS WITH SOLUTIONS 2024
spark plug wire resistance should be - ANSWER 5000 to 10000 ohms
how do you test spark plug cables insulation - ANSWER spray it with salt water
The specification, such as 10 BTDC, indicates that - ANSWER indicates that the spark occurs at 10 degrees
before top dead center of the compression stroke
With an increase in speed, ignition must begin - ANSWER earlier to end by 23 degrees ATDC
Each cylinder must produce power once every - ANSWER 720 degrees
what is the differance between tbi pfi and gdi - ANSWER throttle body injection
port fuel injection
gas direct injection
ideal air to fuel ratio is - ANSWER 14.7:1
EGR valve, air pump, and evaporative emissions canister are controlled by the - ANSWER pcm
what is open loop mode? - ANSWER when the engine is too cold to burn all fuel the engine doesn't
respond to sensor feedback
Fail-Safe or Limp-In Mode - ANSWER ether usses other signals to compensate for out of range sensors or
limits the rpm to 1200
tps adaptive strategy does what - ANSWER if something like the tps drops from its normal range it will
adjust for wear by adding voltage.
,Air induction system - ANSWER An engine system that directs outside air into the engine's intake
manifold
Closed loop - ANSWER An electronic feedback system in which the sensors provide constant information
on what is taking place in the engine
Drive cycle - ANSWER The operating conditions that must exist before OBD II self-diagnosis can take
place. It includes an engine start and operation that brings the vehicle into closed loop and includes
whatever specific operating conditions are necessary, either to initiate and complete a specific
monitoring sequence or to verify a symptom or repair.
Enable criteria - ANSWER The operating conditions that must be met to run some OBD II monitors.
obd2 Freeze frame - ANSWER With this feature of OBD II systems, the PCM takes a snapshot of the
activity of various inputs and outputs at the time the PCM illuminated the MIL
Parameter identification (PID) - ANSWER A scan tool display for OBD II systems that shows current
emission-related data values of inputs and outputs, calculated values, and system status information.
Trip - ANSWER An OBD II drive cycle that includes all of the conditions
basic diagnostic checks 4 - ANSWER 1battery voltage and charging system operation
2check for open fuses
3vissually inspect componants of system
4check for aftermarket parts
what does a scan tool use a PID for - ANSWER obd2 standardized system like the coolant temp sensor
when connecting the scan tool what two things should have been done? - ANSWER get engine at
operating temp set key to off
KOEO self test - ANSWER key on engine off
, KOER self test - ANSWER Key on engine running
obd2 mode 6 data - ANSWER allows to monitor data on any scan tool. can check for missfires. oxogen
sensors ect
visual inspections after finding a dtc - ANSWER check vacuum lines
check belts
check battery and connections
inspect wiring for sensors and outputs
check coolant and condition of it
check air filter and inlet
check for exhaust leaks
if no dtc are present - ANSWER see if data is within normal ranges
pcm power and ground are in good condition
identify all vehical mods
tire inflation
Hard Start/Long Crank
symptom with no dtcs - ANSWER componants/system
Starting System
Fuel/Ignition/Computer
Intake Air System
MAF Sensor
Exhaust System
PCV System
EVAP System