Toyota training course t852 engine control systems sec02

Technician Handbook 874 Engine Control Systems II OBD Generations OBD 10 In 1988, the California Air Resources Board (CARB) set the requirement that all vehicles have a system that could identify faults in the emission and powertrain system This is recognized as OBD I OBD II At the same time OBD requirements were set, CARB also set the requirements for OBD II The federal government adopted these requirements and they went into effect beginning in 1996 OBD II standards greatly enhanced the on-board diagnostic system’s capabilities and changed the way technicians troubleshoot engine and emission control systems CAN OBD II CAN, which stands for Controller Area Network, is a standard (or “protocol”) for high-speed electronic communication CAN OBD II requirements not significantly change the way technicians troubleshoot engine and emission control systems Instead, CAN improves the speed and accuracy of information exchange among the vehicle’s ECUs, and between the vehicle and the diagnostic tester CAN OBD II must be phased in by 2008 Technical Training Technician Handbook 874 Engine Control Systems II TIS Techstream Diagnostic Trouble Codes Screen The TIS Techstream displays all ECU specific DTC information on one screen, including Code name and Description, and specifies it as a Current, Pending, History and/or Permanent DTC The numbers below correspond to the number callouts in the illustration 1.  These columns display the DTC as Current, Pending, History and/or Permanent DTC 2.  Use the eraser button to clear DTC(s), monitor information, etc 3.  To access Freeze Frame data, click on the snowflake icon next to the DTC, or highlight the DTC and click the snowflake button at the bottom of the screen 4.  Use the disc button to store DTC(s), Freeze Frame, and Monitor information to the Stored Data tab If DTCs are not stored from the DTC or Monitor screens, the current DTC and Monitor Status/ Results will not be stored to the Stored Data tab and cannot be accessed later 5.  The current user is displayed here Double-click the current user to access the Change/Create User pop-up window Diagnostic Trouble Codes (DTCs) Diagnostic Trouble Codes are set when the ECM detects a malfunction in a monitored component or system There are two types of DTCs: •  One Trip DTCs •  Two Trip DTCs Technical Training 11 Technician Handbook 874 Engine Control Systems II Trip A trip is defined as an engine-operation drive cycle that contains all of the necessary conditions for a particular test to be performed Some DTC(s) may require a warm-up cycle, while others require just an ignition-ON cycle OBD II Trip An OBD II Trip consists of an engine start following an engine OFF period, with enough vehicle travel time to allow the OBD II monitoring sequences to complete their tests The vehicle must be driven under a variety of operation conditions for ALL tests to be performed Warm-Up Cycle 12 OBD II standards define a warm-up cycle as a period of vehicle operation, after the engine was turned ON, in which coolant temperature rises by at least 40 degrees F (22 degrees C) and reaches at least 160 degrees F (88 degrees C) The ECM determines a cold start by comparing the engine coolant temperature (ECT) and the intake air temperature (IAT) Technical Training Technician Handbook 874 Engine Control Systems II MIL ON One Trip Technical Training There are some DTCs that will set in one trip A one trip DTC will store a code that can be observed in the DTC screen, set a Freeze Frame, and light the MIL Also, depending on model year the DTC will be stored as permanent 13 Technician Handbook 874 Engine Control Systems II MIL ON Two Trip 14 When a two trip emissions-related fault is detected for the first time, a DTC related to that fault is stored as a pending code If the fault occurs again on the second drive cycle, then the DTC is stored as a current, permanent and light the MIL Also, the DTC and Freeze Frame are recorded in memory The pending code will be erased if the monitor test does not detect a fault under the same conditions on the next trip Technical Training Technician Handbook 874 Engine Control Systems II MIL Blinking Technical Training The MIL will blink during the first trip when a misfire occurs that will raise the temperature of the catalytic converter enough to cause damage The blinking may be intermittent because of changes in engine load and the severity of engine misfire If the condition reoccurs during the second trip, the MIL again blinks and the DTC and Freeze Frame are recorded in memory The MIL will be on solid once the DTC is recorded if the misfire is no longer severe enough to damage the catalytic converter See Misfire Diagnosis section for more information 15 Technician Handbook 874 Engine Control Systems II MIL OFF MIL & DTC Summary The MIL is turned OFF after consecutive trips without the fault being detected After the MIL is turned off and 40 successful trips with no fault have been detected, the DTC and Freeze Frame data will be erased from memory; however, the DTC will remain in history until cleared MIL Blinking: •  Misfire detected severe enough to damage the catalytic converter MIL ON: •  One trip fault •  Two trip fault MIL OFF: •  Three consecutive trips, fault not detected, monitor operated DTC Memory Erasure: •  40 trips, fault not detected •  When DTC(s) cleared DTC History: •  DTC is held in history until DTC(s) cleared Freeze Frame Erasure: •  40 trips, fault not detected or when DTC(s) cleared Permanent DTC •  NOTE 16 DTC is erased after three consecutive trips, fault not detected, monitor operated A Pending DTC will be erased after one successful trip where the fault was not detected again Technical Training Technician Handbook 874 Engine Control Systems II Permanent DTC Clearing Permanent DTCs To tighten emission testing standards and decrease the loopholes associated with monitor readiness status (Some state emission testing allow up to two monitors to be “Incomplete” at the time of inspection without failing the test) Permanent DTCs were designed to set anytime the MIL is commanded on and cannot be erased from memory until the fault is corrected and normal judgment is determined Permanent DTCs will be standard on all Toyota models by 2010 model year Clearing DTCs can no longer be accomplished solely by the eraser button on Techstream There are two methods to successfully clear Permanent DTCs: •  The vehicle is driven for consecutive trips and normal judgment is confirmed by associated monitors •  Technical Training After clearing DTCs with Techstream or disconnecting the negative battery terminal, the ECM must see normal judgment for the respective DTC by completing two drive patterns: Confirmation Driving Pattern and an Universal Trip Driving Pattern 17 Technician Handbook 874 Engine Control Systems II Confirmation Driving Pattern The Confirmation Driving Pattern is used to provide DTC specific vehicle operation to confirm normal judgment This driving pattern is specific for each DTC and system monitoring strategy After normal judgment is obtained the Universal Trip Driving Pattern will need to be completed to fully clear the permanent DTC column (or three consecutive drive cycles with normal judgment) Universal Trip Driving Pattern The Universal Trip Driving Pattern (UTDP) can be performed consecutively with the Confirmation Drive Pattern Be sure to let the engine idle for 30 or more seconds before proceeding and drive the vehicle at 25 mph or more for at least minutes NOTE 18 It is possible to complete the drive pattern even if the vehicle decelerates below 25 mph during drive cycle provided that the vehicle is driven at or above 25 mph for a total of minutes Allow 10 minutes or more to elapse from the time the engine is started and cycle the ignition to confirm the permanent DTCs have been cleared Technical Training Technician Handbook 874 Engine Control Systems II OBD II Diagnostic Trouble Codes (DTC) OBD II DTCs must follow a standardized format set by the Society of Automotive Engineers (SAE) The following is a summary of the DTC standardized format: •  Stored when fault confirmed (one or two trip) •  Remains active for 40 cycles (without fault) •  Freeze Frame stored •  Remains in history until cleared The first digit indicates component area group •  Example: P = Powertrain, B = Body, etc The second digit indicates SAE controlled or manufacturer specific •  Example: = SAE controlled, = manufacturer specific, = SAE controlled, = manufacturer specific and SAE reserved The third digit indicates DTC subgroup •  Example: = total system, = fuel and air metering, etc The fourth and fifth digits indicate area or component involved •  Example: 71 = Fuel Trim Technical Training 19 Technician Handbook 874 Engine Control Systems II Cumulative Monitor The Cumulative Monitor displays readiness monitors that have run and completed at least one trip since the Monitor was last reset (DTCs Cleared) The Cumulative Monitor displays Test Results and Test Details for the previous Monitor trip When monitors are reset (DTCs Cleared), Cumulative Monitor status and result fields change to Incomplete and Pass Cumulative Monitor information can be used during emission testing to verify that each Monitor has run, completed and passed at least one trip since the Monitor was last reset (DTCs Cleared) Technical Training 27 Technician Handbook 874 Engine Control Systems II Current Monitor The Current Monitor screen shows current trip information When the key is first turned ON and the engine is OFF, Monitor Status and Monitor Results will show information from the last key cycle When the engine has started and is running, Monitor Status and Monitor Results will reset to Incomplete and Pass Test Results and Test Details will continue to display last trip values until the monitor runs and completes the current trip When the Monitor completes, Monitor Status, Monitor Results, Test Results and Test Details are updated with latest trip information Current Monitor information can be used as an advanced diagnostic tool to confirm system/component failures, system operation and readiness monitor operation 28 Technical Training Technician Handbook 874 Engine Control Systems II Continuous Monitors Continuous monitors test components and systems many times per trip when enabling conditions are met Continuous monitored components and systems are: •  Misfire (See Misfire Diagnosis section for more information.) •  Fuel System (See Fuel System Diagnosis section for more information.) •  Comprehensive Components (Composition Parts) (See Comprehensive Components Monitor Diagnosis section for more information.) Continuous monitor DTCs can set anytime the DTC enabling conditions are met Examples include: •  DTC P0171 – Fuel System Lean (Bank 1) will set with the engine ON when average fuel trim becomes higher than a predetermined value (See Fuel System Diagnosis section for more information.) •  DTC P0113 – Intake Air Temperature Circuit High Input will set with ignition ON immediately after MAF sensor connector is disconnected (See Comprehensive Components Monitor Diagnosis section for more information.) Continuous monitors will be displayed with an infinity symbol in the Summary column of the monitor information screen in Techstream Technical Training 29 Technician Handbook 874 Engine Control Systems II Non-Continuous Monitors Non-continuous monitors test components and systems one time, conditions permitting, per trip Non-continuous monitored components and systems are: •  Catalyst Efficiency (See Catalytic Converter Diagnosis section for more information.) •  Heated Catalyst (Toyota/Lexus vehicles not utilize Heated Catalysts, so this monitor is not supported.) •  Evaporative System (See EVAP Diagnosis section for more information.) •  2nd Air System (See Secondary Air Injection System Diagnosis section for more information.) •  A/C System (Toyota/Lexus vehicles not monitor the A/C system, so this monitor is not supported.) •  O2 Sensor (See O2 and A/F Sensor Diagnosis section for more information.) •  O2 Sensor Heater (See O2 and A/F Sensor Diagnosis section for more information.) •  Exhaust Gas Recirculation / VVT (See Additional Systems for more information.) 30 Technical Training Technician Handbook 874 Engine Control Systems II Non-Continuous Monitors (cont’d) To complete testing, most non-continuous monitors require a Readiness Monitor Drive Pattern to be followed See the NonContinuous Readiness Monitor Drive Patterns portion of this section for more information Non-continuous DTCs will only be set after the monitor specific to the DTC completes testing Examples include: •  DTC P0420 – Catalyst System Efficiency Below Threshold (Bank 1) will set after the Catalyst Readiness Monitor Drive Pattern has been followed and the monitor completes testing See Catalytic Converter Diagnosis section for more information •  DTC P0456 – Evaporative System Gross Leak Detected will set after the Key-OFF EVAP Monitor has completed testing This is why the MIL may be ON immediately at next ignition ON after the monitor completed testing See EVAP Diagnosis section for more information Technical Training 31 Technician Handbook 874 Engine Control Systems II Non-Continuous Readiness Monitor Drive Patterns In order for readiness monitors to complete testing, the vehicle must be driven according to Readiness Monitor Drive Patterns To complete testing, each readiness monitor will require a specific drive pattern be followed Readiness Monitor Drive Patterns are specific to vehicle model year, make, and model For model year 1996–2003 vehicles, the monitor drive patterns can be accessed in the RM section of TIS2, found in a document entitled “OBD II: General Information.” The readiness monitor drive patterns are in the General  General Information  OBD Monitor Drive Patterns section of this document This document contains a variety of important information, and it may be helpful to print this entire document for your reference For model year 2004 and later, the monitor drive patterns can be accessed from the Readiness Monitor Drive Pattern section of the vehicle Repair Manual 32 The Catalyst Monitor Drive Pattern In order for the Catalyst monitor to complete testing, first, the engine must reach operating temperature at idle Next, the vehicle must be driven between 40 mph and 70 mph (63 km/h and 113 km/h) for approximately ten (10) minutes The drive pattern will need to be repeated if the monitor does not complete testing A/F and HO2 Sensor Monitor Drive Pattern Parts “A, B, & C” are identical to the Catalyst Monitor drive pattern with the addition of at least fuel-cut cycles Accelerate the vehicle to 40 MPH or more for at least 10 seconds Soon after performing acceleration cycle, release the accelerator pedal for at least seconds without depressing the brake pedal Allow the vehicle to decelerate until the vehicle’s speed reaches mph or less Repeat this process at least times or until monitor status switches to complete Technical Training Technician Handbook 874 Engine Control Systems II Interpreting Non-Continuous Readiness Monitors Status and Results Understanding Readiness Monitors Status and Results will help to duplicate concerns and verify repairs The following is a guide to interpret non-continuous Readiness Monitors Status and Results: Status States whether or not the monitor meets all the enabling conditions to proceed with testing If the status is Ready the monitor is enabled, Not Ready the monitor does not meet the criteria to proceed Cumulative/Current States the test status for that particular monitor When the monitor finishes all testing, the column will read Complete If testing has not begun or is only partially complete the column will read Incomplete Result Reports if the monitor passed or failed Default value is Pass, and Fail indicates a malfunction was found during testing Summary Symbols indicate the present monitor status and can be used easily to determine the present status of the monitor Technical Training 33 Technician Handbook 874 Engine Control Systems II Interpreting Monitor Status Ready, Complete, Pass If Status is Ready, Current displays Complete and Result displays Pass then the monitor completed testing and passed this trip Check Test Details for all Readiness Monitors to ensure tests are passing well within the Min Limit and Max Limit thresholds (see Readiness Monitors Test Details topic for more information) Ready, Incomplete or Complete, Fail If Status is Ready, Current displays Incomplete or Complete and Result displays Fail then the monitor ran and failed this trip An issue with the system currently exists and a DTC is present Diagnosis and repair is necessary Ready, Incomplete, Pass If Status is Ready, Current displays Incomplete and Result displays Pass then the monitor has not completed testing this trip This is the default setting This may be due to: the enabling conditions were not met, the monitor did not complete operating, or the ECM is withholding judgment Drive the vehicle per the appropriate Readiness Monitor Drive Pattern or perform the system check (if applicable) to run the monitor Then re-check the Monitor Information screen Not Ready, Incomplete, Pass or Fail If Status is Not Ready, Current displays Incomplete and Result displays Pass or Fail then the monitor has been disabled and cannot proceed with testing This may be due to: the enabling conditions were not met or disabled If DTCs are present, diagnose these DTCs first before proceeding with monitor testing No Result Information If Result does not display information, the monitor is not supported and will not run NOTE 34 Monitor Information will not update when in Monitor mode To see the most current information, exit out of Monitor mode, then enter back into it Technical Training Technician Handbook 874 Engine Control Systems II Readiness Monitor Test Results Each readiness monitor runs a series of tests If one test fails, the monitor fails and a DTC is set specific to the test Test Results can be accessed by clicking the magnifying glass icon in the Details column of the Monitor Information screen The Result column of the Test Results pop-up window will display Pass or Fail, depending on the result of the test The Test Description portion of the Test Results window will display a description of the specific test that is highlighted In the illustration, Pending DTC P0156 – Oxygen Sensor Circuit Malfunction (Bank Sensor 2) was set when the MIN, Max Voltage & MAX OSC tests failed Min, Max Limits, and Test Value represent the test criteria from the last trip the monitor test completed Depending on the Status/ Current and Result of specific readiness monitors, Test Results will display information from different trips If Current is Complete and Result is Pass, Test Results will display information from this trip If Current is Incomplete and Result is Pass, Test Results will display information from the last trip the monitor test completed In the illustration, the O2 Sensor readiness monitor Max Voltage test value is less than the Min Limit threshold, resulting in a Fail condition Technical Training 35 Technician Handbook 874 Engine Control Systems II Readiness Monitor Test Results (cont’d) 36 NOTE If an intermittent MIL ON condition exists, a Monitor Test Result Value may be crossing over a limit threshold After a repair attempt has been made, clear DTCs and run the monitor again If the same Monitor Test Result Value is well within the Min and Max Limit thresholds, the repair was successful NOTE The Min Limit, Max Limit, and Test Value readings may not correlate to the values in the Repair Manual Always reference the malfunction threshold in the Repair Manual to determine DTC specific Min/Max Limits To use Test Results, make sure the Test Value is within the Min Limit and Max Limit If the Test Value is within the Min Limit and Max Limit after a repair, the repair was probably successful Technical Training Technician Handbook 874 Engine Control Systems II Readiness Monitor Test Details – DTCs Cleared If a readiness monitor test has not completed testing since DTC(s) were cleared, Test Results will display incomplete information Min Limit, Max Limit, and Test Value will display incomplete values If the readiness monitor Test Results displays incomplete information, drive the vehicle per the appropriate Readiness Monitor Drive Pattern or perform the system check (if applicable) to run the monitor Then, re-check the Monitor Information screen Technical Training 37 Technician Handbook 874 Engine Control Systems II 38 Technical Training Technician Handbook 874 Engine Control Systems II Utility Technical Training Use the Utility function to perform applicable System Checks, place the TIS Techstream into Check Mode, change customizable vehicle functions, and perform other utility functions specific to the live ECU 39 Technician Handbook 874 Engine Control Systems II Check Mode Placing the ECM into Check Mode will set two trip DTCs to one trip and tighten the DTC detection criteria so that DTCs will set more easily This mode can aid in diagnosis To activate Check Mode with the TIS Techstream, go to the Engine (and ECT) Live tab  Utility  Check Mode and follow the prompts To return to Normal Mode, turn the ignition switch OFF for twenty (20) seconds A Check Mode data list parameter can be viewed in the Data List ON indicates the system is in Check Mode OFF indicates the system is in Normal Mode 40 NOTE When switching Check Mode ON or OFF, all DTCs, Freeze Frame data, and Monitor information will be erased NOTE Check Mode does not affect two trip EVAP DTCs NOTE Check Mode will disable the misfire monitor Technical Training Technician Handbook 874 Engine Control Systems II Technical Training 41 ... Information screen Technical Training 37 Technician Handbook 874 Engine Control Systems II 38 Technical Training Technician Handbook 874 Engine Control Systems II Utility Technical Training Use the Utility... to control specific components in order to test them for proper operation and electrical control Active tests can aid in diagnosis Technical Training Technician Handbook 874 Engine Control Systems. .. comparing the engine coolant temperature (ECT) and the intake air temperature (IAT) Technical Training Technician Handbook 874 Engine Control Systems II MIL ON One Trip Technical Training There