Week 1, Chapter 64 - OBD Flashcards
What light is illuminated when a vehicle has identified a fault that is likely causing it not to comply with clean air regulations?
Check Engine Light
The ____ runs the engine management systems through self-tests at engine start-up and continues to monitor the systems once underway
PCM
What kind of computers monitor systems and components and inform vehicle operator when a fault occurs?
Onboard Diagnostic (OBD) Systems
Which OBD generation includes these…
- Became nationwide in 1981
- Allowed each vehicle manufacturer to have its own OBD system
- No set standards for DTC’s
- Basic information from a scan tool
- Flash diagnostics
OBD I
Which OBD generation includes these…
- Operate under standards set by SAE
- Standardized nationwide in 1996
- Constantly monitor and manage the engine management system
OBD II
- Sensor data can be accessed with a scan tool
- Scan tool can be used to access the information from any sensor in the system
- All of the sensor data can be examined while diagnosing faults
These this are all included in what?
Data Stream, or Parameter Identification (PID)
A ____________ is a localized vehicle network that enables computers and components to send and receive signals across a shielded twisted pair of wires
CANbus
What kind of wires are shielded by being twisted around one another and carry balanced signals between modules?
Twisted Pair Wires
An ignition cycle in which the key is turned on, a monitor runs, the key is turned off and the PCM powers down
Trip
A trip when the engine is started and run until the engine operating temperature reaches 160°F and has increased in temperature at least 40°F and the engine is turned off again
Warm-up Cycle
When all monitors have run and passed (this may take a very long time)
Drive Cycle
Conditions that must be met for a monitor to run such as certain temperatures, speed, what the sensor is being used for at the time, etc.
Enabling Criteria
The conditions that were occurring when a monitor failed
Similar Conditions Window
A snapshot of parameters taken on the first failure of a monitor
Freeze Frame Data
Live data or freeze frame data that provides sensor and actuator information to the technician
Parameter Identification (PID)
_____________________ is a list of sensor data that are associated with a specific DTC and is listed in order of highest priority to lowest priority DTC’s
Freeze Frame Data
___________ indicate the component or circuit in which a fault has been detected and are stored in one or more of the vehicle’s electronic control modules
Diagnostic Trouble Codes (DTCs)
Once the MIL is on, it will remain on until either the technician clears the codes, or the fault has not been detected during ____ consecutive trips when the monitor is run without failure
3
Pending/current codes that have happened in the past, but haven’t been cleared manually with a scan tool, and will stay for up to 80 warm up cycles depending on the severity of the fault
History Codes
_________ DTC’s are priority. These set the check engine light on the first failure of a monitor, and if the problem is severe enough, the check engine light will flash in order to alert the driver that there is something causing damage to the emission control systems of the vehicle.
Type A
_________ DTC’s are generally a two-trip fault in which freeze frame data is set on the first failure of a monitor and on the second failure, the MIL is illuminated
Type B
________ DTC’s are non-priority for emissions. These include:
- ABS, TCS, Restraints, Oil change reminders, maintenance reminders, etc.
Type C
Position 1 of a DTC determines the…
Major System at fault
Position 2 of a DTC determines the…
Determination
