Chapter 11 OBD Part 2
List 4 common conditions necessary for a drive cycle to successfully run:
1. @ cold start, IAT & ECT close in temperature 2. Fuel within range (15% to 85%) 3. Specified range of time 4 to 12 minutes 4. @ stop & idle for certain time
Mode 6 can help diagnose faults by following these three steps:
1. How system failed 2. what is required to pass monitor 3. What triggered the fault
List 5 of 10 Freeze Frame Data
1. Load 2. RPM 3. Fuel Trim 4. Fuel Pressure 5. Vehicle Speed
List 4 reasons a continuous monitor may be stopped.
1. Misfire 2. 2 trip fault 3. fuel too rich/lean 4. Freeze Frame activaated
Describe the 4 major codes:
1. P Codes = Powertrain/engines 2. B Codes = Body/Interior 3. C Codes = Chassis/suspension 4. U Codes = Communication module
OBD2 has been on all passenger vehicles in the U.S. since ____.
1996
The computer will automatically clear a DTC if there are no additional detected faults after _____.
40 Consecutive warm up cycles
What is a Trip?
A Key on condition to run particular tests
DTC P0302 is a _____.
A generic DTC
P0100 code are from system in:
Air Metering & Fuel
What are pending codes and how do they differ from a fault code?
Component not in range, yet has not met the conditions to set a DTC
What condition exist if the MIL light is steady?
Fault related to emissions
P0200 codes are from system in:
Fuel Injector
Which is a continuous monitor?
Fuel system monitor
P0302: What does the second digit represent?
Generic or Manufacturer specific
Global (generic) OBD2 contains some data in what format?
Hexidecimal
P0300 codes are from what system?
Ignition System or Misfire
What condition exist if the MIL light is flashing?
Misfire or fuel control system fault that can damage CAT
List the description of the 9 modes of operation:
Mode 1: Parameter Identification Display Mode 2: Freeze Frame Data Mode 3: DTC's Mode 4: Clear Codes Mode 5: O2 Sensor Monitor Mode 6: Non Continuous Monitoring Mode 7: Continuously Monitoring Mode 8: Bidirectional Control Mode 9: Module Identification
What is the enabling criteria for an EGR monitor?
No start when @ idle
The comprehensive component monitor checks comuter controlled devices for _____.
Opens Shorts to ground Rationality
The PCM can check the inputs and outputs electrically by detecting _____, _____, and _____.
Opens, shorts, and grounds
By looking at the way DTC's are formatted, which DTC could indicate that the gas cap is loose or defective?
P0442
What is the enabling criteria for an O2 sensor monitor?
Reaching operating temperature and entered close loop
Rationality Test are usually with PCM _____ and Functionality test are related to PCM _____.
Sensor Inputs PCM Outputs
P0302: What does the fourth and fifth digits represent?
Specific Fault Designation
P0302: What does the third digit represent?
The Specific System
A pending code is a set when a fault is detected on_____.
The first fault of a two trip failure
An ignition misfire or fuel mixture problem is an example of what type of DTC?
Type A
Emission related Codes are of what type?
Type A & or Type B
What is a drive cycle?
Vehicle driven @ certain speeds during certain times that allow monitors to run
A freeze frame is generated on an OBD2 vehicle _____.
When a type A or B diagnostic trouble code is set
What is Freeze Frame Data?
snapshot or still of all data @ time of emissions DTC is set
How long will the fault code remain in memory?
up until 40 warm up cycles with temperatures above 160⁰F
What website has information on each manufacture's service information website that provide mode 6 data?
www.NASTF.com