Emissions Control Jeep Grand Cherokee WK2

STATE DISPLAY TEST MODE

The switch inputs to the Powertrain Control Module (PCM) have two recognized states; HIGH and LOW. For this reason, the PCM cannot recognize the difference between a selected switch position versus an open circuit, a short circuit, or a defective switch. If the State Display screen shows the change from HIGH to LOW or LOW to HIGH, assume the entire switch circuit to the PCM functions properly. Connect a diagnostic scan tool to the data link connector and access the state display screen. Then access either State Display Inputs and Outputs or State Display Sensors.

CIRCUIT ACTUATION TEST MODE

The Circuit Actuation Test Mode checks for proper operation of output circuits or devices the Powertrain Control Module (PCM) may not internally recognize. The PCM attempts to activate these outputs and allow an observer to verify proper operation. Most of the tests provide an audible or visual indication of device operation (click of relay contacts, fuel spray, etc.). Except for intermittent conditions, if a device functions properly during testing, assume the device, its associated wiring, and driver circuit work correctly. Connect a scan tool to the data link connector and access the Actuators screen.

DIAGNOSTIC TROUBLE CODES

A Diagnostic Trouble Code (DTC) indicates the PCM has recognized an abnormal condition in the system.

Remember that DTC's are the results of a system or circuit failure, but do not directly identify the failed component or components.

BULB CHECK

Each time the ignition key is turned to the ON position, the malfunction indicator (check engine) lamp on the instrument panel should illuminate for approximately 2 seconds then go out. This is done for a bulb check.

OBTAINING DTC'S

1. Obtain the applicable Powertrain Diagnostic Information.
2. Obtain the appropriate scan tool.
3. Connect the appropriate scan tool to the data link (diagnostic) connector. This connector is located in the passenger compartment; at the lower edge of instrument panel; near the steering column.
4. Turn the ignition switch on and access the "Read Fault" screen.
5. Record all the DTC's and "freeze frame" information shown on the appropriate scan tool.
6. To erase DTC's, use the "Erase Trouble Code" data screen on the appropriate scan tool. Do not erase any DTC's until problems have been investigated and repairs have been performed.

TASK MANAGER

The PCM is responsible for efficiently coordinating the operation of all the emissions-related components. The PCM is also responsible for determining if the diagnostic systems are operating properly. The software designed to carry out these responsibilities is call the 'Task Manager'.

TRIP DEFINITION

The term "Trip" has different meanings depending on what the circumstances are. If the MIL (Malfunction Indicator Lamp) is OFF, a Trip is defined as when the Oxygen Sensor Monitor and the Catalyst Monitor have been completed in the same drive cycle.

When any Emission DTC is set, the MIL on the dash is turned ON. When the MIL is ON, it takes 3 good trips to turn the MIL OFF. In this case, it depends on what type of DTC is set to know what a "Trip" is.

For the Fuel Monitor or Mis-Fire Monitor (continuous monitor), the vehicle must be operated in the "Similar Condition Window" for a specified amount of time to be considered a Good Trip.

If a Non-Contiuous OBDII Monitor fails twice in a row and turns ON the MIL, re-running that monitor which previously failed, on the next start-up and passing the monitor, is considered to be a Good Trip. These will include the following

1. Oxygen Sensor
2. Catalyst Monitor
3. Purge Flow Monitor
4. Leak Detection Pump Monitor (if equipped)
5. EGR Monitor (if equipped)
6. Oxygen Sensor Heater Monitor

If any other Emission DTC is set (not an OBDII Monitor), a Good Trip is considered to be when the Oxygen Sensor Monitor and Catalyst Monitor have been completed; or 2 Minutes of engine run time if the Oxygen Sensor Monitor or Catalyst Monitor have been stopped from running.

It can take up to 2 Failures in a row to turn on the MIL. After the MIL is ON, it takes 3 Good Trips to turn the MIL OFF. After the MIL is OFF, the PCM will self-erase the DTC after 40 Warm-up cycles. A Warm-up cycle is counted when the ECT (Engine Coolant Temperature Sensor) has crossed 71°C (160°F) and has risen by at least 4°C (40°F) since the engine has been started.

COMPONENT MONITORS

There are several components that will affect vehicle emissions if they malfunction. If one of these components malfunctions the Malfunction Indicator Lamp (MIL) will illuminate.

Some of the component monitors are checking for proper operation of the part. Electrically operated components now have input (rationality) and output (functionality) checks. Previously, a component like the Throttle Position sensor (TPS) was checked by the PCM for an open or shorted circuit. If one of these conditions occurred, a DTC was set. Now there is a check to ensure that the component is working. This is done by watching for a TPS indication of a greater or lesser throttle opening than MAP and engine rpm indicate. In the case of the TPS, if engine vacuum is high and engine rpm is 1600 or greater, and the TPS indicates a large throttle opening, a DTC will be set. The same applies to low vacuum if the TPS indicates a small throttle opening.

All open/short circuit checks, or any component that has an associated limp-in, will set a fault after 1 trip with the malfunction present. Components without an associated limp-in will take two trips to illuminate the MIL.

The Task Manager determines which tests happen when and which functions occur when. Many of the diagnostic steps required by OBD II must be performed under specific operating conditions. The Task Manager software organizes and prioritizes the diagnostic procedures. The job of the Task Manager is to determine if conditions are appropriate for tests to be run, monitor the parameters for a trip for each test, and record the results of the test. Following are the responsibilities of the Task Manager software

1. Test Sequence
2. MIL Illumination
3. Diagnostic Trouble Codes (DTCs)
4. Trip Indicator
5. Freeze Frame Data Storage
6. Similar Conditions Window

TEST SEQUENCE

In many instances, emissions systems must fail diagnostic tests more than once before the PCM illuminates the MIL. These tests are know as 'two trip monitors.' Other tests that turn the MIL lamp on after a single failure are known as 'one trip monitors.' A trip is defined as 'start the vehicle and operate it to meet the criteria necessary to run the given monitor.'

Many of the diagnostic tests must be performed under certain operating conditions. However, there are times when tests cannot be run because another test is in progress (conflict), another test has failed (pending) or the Task Manager has set a fault that may cause a failure of the test (suspend).

1. Pending Under some situations the Task Manager will not run a monitor if the MIL is illuminated and a fault is stored from another monitor. In these situations, the Task Manager postpones monitors pending resolution of the original fault. The Task Manager does not run the test until the problem is remedied. For example, when the MIL is illuminated for an Oxygen Sensor fault, the Task Manager does not run the Catalyst Monitor until the Oxygen Sensor fault is remedied. Since the Catalyst Monitor is based on signals from the Oxygen Sensor, running the test would produce inaccurate results.
2. Conflict There are situations when the Task Manager does not run a test if another monitor is in progress. In these situations, the effects of another monitor running could result in an erroneous failure. If this conflict is present, the monitor is not run until the conflicting condition passes. Most likely the monitor will run later after the conflicting monitor has passed. For example, if the Fuel System Monitor is in progress, the Task Manager does not run the EGR Monitor. Since both tests monitor changes in air/fuel ratio and adaptive fuel compensation, the monitors will conflict with each other.
3. Suspend Occasionally the Task Manager may not allow a two trip fault to mature. The Task Manager will suspend the maturing of a fault if a condition exists that may induce an erroneous failure. This prevents illuminating the MIL for the wrong fault and allows more precis diagnosis. For example, if the PCM is storing a one trip fault for the Oxygen Sensor and the EGR monitor, the Task Manager may still run the EGR Monitor but will suspend the results until the Oxygen Sensor Monitor either passes or fails. At that point the Task Manager can determine if the EGR system is actually failing or if an Oxygen Sensor is failing.

MIL ILLUMINATION

The PCM Task Manager carries out the illumination of the MIL. The Task Manager triggers MIL illumination upon test failure, depending on monitor failure criteria.

The Task Manager Screen shows both a Requested MIL state and an Actual MIL state. When the MIL is illuminated upon completion of a test for a third trip, the Requested MIL state changes to OFF. However, the MIL remains illuminated until the next key cycle. (On some vehicles, the MIL will actually turn OFF during the third key cycle) During the key cycle for the third good trip, the Requested MIL state is OFF, while the Actual MILL state is ON. After the next key cycle, the MIL is not illuminated and both MIL states read OFF.

DIAGNOSTIC TROUBLE CODES (DTCS)

With OBD II, different DTC faults have different priorities according to regulations. As a result, the priorities determine MIL illumination and DTC erasure. DTCs are entered according to individual priority. DTCs with a higher priority overwrite lower priority DTCs.

Priorities

1. Priority 0 -Non-emissions related trouble codes
2. Priority 1 - One trip failure of a two trip fault for non-fuel system and non-misfire.
3. Priority 2 - One trip failure of a two trip fault for fuel system (rich/lean) or misfire.
4. Priority 3 - Two trip failure for a non-fuel system and non-misfire or matured one trip comprehensive component fault.
5. Priority 4 - Two trip failure or matured fault for fuel system (rich/lean) and misfire or one trip catalyst damaging misfire.

Non-emissions related failures have no priority. One trip failures of two trip faults have low priority. Two trip failures or matured faults have higher priority. One and two trip failures of fuel system and misfire monitor take precedence over non-fuel system and non-misfire failures.

DTC SELF ERASURE

With one trip components or systems, the MIL is illuminated upon test failure and DTCs are stored.

Two trip monitors are components requiring failure in two consecutive trips for MIL illumination. Upon failure of the first test, the Task Manager enters a maturing code. If the component fails the test for a second time the code matures and a DTC is set.

After three good trips the MIL is extinguished and the Task Manager automatically switches the trip counter to a warm-up cycle counter. DTCs are automatically erased following 40 warm-up cycles if the component does not fail again.

For misfire and fuel system monitors, the component must pass the test under a Similar Conditions Window in order to record a good trip. A Similar Conditions Window is when engine RPM is within ±375 RPM and load is within ±10% of when the fault occurred.

Note. It is important to understand that a component does not have to fail under a similar window of operation to mature. It must pass the test under a Similar Conditions Window when it failed to record a Good Trip for DTC erasure for misfire and fuel system monitors.

DTCs can be erased anytime with a diagnostic scan tool. Erasing the DTC with the scan tool erases all OBD II information. The scan tool automatically displays a warning that erasing the DTC will also erase all OBD II monitor data. This includes all counter information for warm-up cycles, trips and Freeze Frame.

TRIP INDICATOR

The Trip is essential for running monitors and extinguishing the MIL. In OBD II terms, a trip is a set of vehicle operating conditions that must be met for a specific monitor to run. All trips begin with a key cycle.

GOOD TRIP

The Good Trip counters are as follows

1. Specific Good Trip
2. Fuel System Good Trip
3. Misfire Good Trip
4. Alternate Good Trip (appears as a Global Good Trip on a scan tool) Comprehensive Components Major Monitor
5. Warm-Up Cycles

SPECIFIC GOOD TRIP

The term Good Trip has different meanings depending on the circumstances

1. If the MIL is OFF, a trip is defined as when the Oxygen Sensor Monitor and the Catalyst Monitor have been completed in the same drive cycle.
2. If the MIL is ON and a DTC was set by the Fuel Monitor or Misfire Monitor (both continuous monitors), the vehicle must be operated in the Similar Condition Window for a specified amount of time.
3. If the MIL is ON and a DTC was set by a Task Manager commanded once-per-trip monitor (such as the Oxygen Sensor Monitor, Catalyst Monitor, Purge Flow Monitor, Leak Detection Pump Monitor, EGR Monitor or Oxygen Sensor Heater Monitor), a good trip is when the monitor is passed on the next start-up.
4. If the MIL is ON and any other emissions DTC was set (not an OBD II monitor), a good trip occurs when the Oxygen Sensor Monitor and Catalyst Monitor have been completed, or two minutes of engine run time if the Oxygen Sensor Monitor and Catalyst Monitor have been stopped from running.

FUEL SYSTEM GOOD TRIP

To count a good trip (three required) and turn off the MIL, the following conditions must occur

1. Engine in closed loop
2. Operating in Similar Conditions Window
3. Short Term multiplied by Long Term less than threshold
4. Less than threshold for a predetermined time

If all of the previous criteria are met, the PCM will count a good trip (three required) and turn off the MIL.

MISFIRE GOOD TRIP

If the following conditions are met the PCM will count one good trip (three required) in order to turn off the MIL

1. Operating in Similar Condition Window
2. 1000 engine revolutions with no misfire

WARM-UP CYCLES

Once the MIL has been extinguished by the Good Trip Counter, the PCM automatically switches to a Warm-Up Cycle Counter that can be viewed on a diagnostic scan tool. Warm-Up Cycles are used to erase DTCs and Freeze Frames. Forty Warm-Up cycles must occur in order for the PCM to self-erase a DTC and Freeze Frame. A Warm-Up Cycle is defined as follows

1. Engine coolant temperature must start below and rise above 71°C (160° F)
2. Engine coolant temperature must rise by 4°C (40° F)
3. No further faults occur

FREEZE FRAME DATA STORAGE

Once a failure occurs, the Task Manager records several engine operating conditions and stores it in a Freeze Frame. The Freeze Frame is considered one frame of information taken by an on-board data recorder. When a fault occurs, the PCM stores the input data from various sensors so that technicians can determine under what vehicle operating conditions the failure occurred.

The data stored in Freeze Frame is usually recorded when a system fails the first time for two trip faults. Freeze Frame data will only be overwritten by a different fault with a higher priority.

SIMILAR CONDITIONS WINDOW

The Similar Conditions Window displays information about engine operation during a monitor. Absolute MAP (engine load) and Engine RPM are stored in this window when a failure occurs. There are two different Similar conditions Windows: Fuel System and Misfire.

FUEL SYSTEM

1. Fuel System Similar Conditions Window - An indicator that 'Absolute MAP When Fuel Sys Fail' and 'RPM When Fuel Sys Failed' are all in the same range when the failure occurred. Indicated by switching from 'NO' to 'YES'.
2. Absolute MAP When Fuel Sys Fail - The stored MAP reading at the time of failure. Informs the user at what engine load the failure occurred.
3. Absolute MAP - A live reading of engine load to aid the user in accessing the Similar Conditions Window.
4. RPM When Fuel Sys Fail - The stored RPM reading at the time of failure. Informs the user at what engine RPM the failure occurred.
5. Engine RPM - A live reading of engine RPM to aid the user in accessing the Similar Conditions Window.
6. Adaptive Memory Factor - The PCM utilizes both Short Term Compensation and Long Term Adaptive to calculate the Adaptive Memory Factor for total fuel correction.
7. Upstream O2S Volts - A live reading of the Oxygen Sensor to indicate its performance. For example, stuck lean, stuck rich, etc.
8. SCW Time in Window (Similar Conditions Window Time in Window) - A timer used by the PCM that indicates that, after all Similar Conditions have been met, if there has been enough good engine running time in the SCW without failure detected. This timer is used to increment a Good Trip.
9. Fuel System Good Trip Counter - A Trip Counter used to turn OFF the MIL for Fuel System DTCs. To increment a Fuel System Good Trip, the engine must be in the Similar Conditions Window, Adaptive Memory Factor must be less than calibrated threshold and the Adaptive Memory Factor must stay below that threshold for a calibrated amount of time.
10. Test Done This Trip - Indicates that the monitor has already been run and completed during the current trip.

MISFIRE

1. Same Misfire Warm-Up State - Indicates if the misfire occurred when the engine was warmed up (above 71°C (160° F).
2. In Similar Misfire Window - An indicator that 'Absolute MAP When Misfire Occurred' and 'RPM When Misfire Occurred' are all in the same range when the failure occurred. Indicated by switching from 'NO' to 'YES'.
3. Absolute MAP When Misfire Occurred - The stored MAP reading at the time of failure. Informs the user at what engine load the failure occurred.
4. Absolute MAP - A live reading of engine load to aid the user in accessing the Similar Conditions Window.
5. RPM When Misfire Occurred - The stored RPM reading at the time of failure. Informs the user at what engine RPM the failure occurred.
6. Engine RPM - A live reading of engine RPM to aid the user in accessing the Similar Conditions Window.
7. Adaptive Memory Factor - The PCM utilizes both Short Term Compensation and Long Term Adaptive to calculate the Adaptive Memory Factor for total fuel correction.
8. 200 Rev Counter - Counts 0-100 720 degree cycles.
9. SCW Cat 200 Rev Counter - Counts when in similar conditions.
10. SCW FTP 1000 Rev Counter - Counts 0-4 when in similar conditions.
11. Misfire Good Trip Counter - Counts up to three to turn OFF the MIL.
12. Misfire Data - Data collected during test.
13. Test Done This Trip - Indicates YES when the test is done.

DESCRIPTION

The PCM does not monitor the following circuits, systems and conditions that could have malfunctions causing driveability problems. The PCM might not store diagnostic trouble codes for these conditions. However, problems with these systems may cause the PCM to store diagnostic trouble codes for other systems or components. EXAMPLE: a fuel pressure problem will not register a fault directly, but could cause a rich/lean condition or misfire. This could cause the PCM to store an oxygen sensor or misfire diagnostic trouble code

FUEL PRESSURE

The fuel pressure regulator controls fuel system pressure. The PCM cannot detect a clogged fuel pump inlet filter, clogged in-line fuel filter, or a pinched fuel supply or return line. However, these could result in a rich or lean condition causing the PCM to store an oxygen sensor or fuel system diagnostic trouble code.

SECONDARY IGNITION CIRCUIT

The PCM cannot detect an inoperative ignition coil, fouled or worn spark plugs, ignition cross firing, or open spark plug cables.

CYLINDER COMPRESSION

The PCM cannot detect uneven, low, or high engine cylinder compression.

EXHAUST SYSTEM

The PCM cannot detect a plugged, restricted or leaking exhaust system, although it may set a fuel system fault.

FUEL INJECTOR MECHANICAL MALFUNCTIONS

The PCM cannot determine if a fuel injector is clogged, the needle is sticking or if the wrong injector is installed. However, these could result in a rich or lean condition causing the PCM to store a diagnostic trouble code for either misfire, an oxygen sensor, or the fuel system.

EXCESSIVE OIL CONSUMPTION

Although the PCM monitors engine exhaust oxygen content when the system is in closed loop, it cannot determine excessive oil consumption.

THROTTLE BODY AIR FLOW

The PCM cannot detect a clogged or restricted air cleaner inlet or filter element.

VACUUM ASSIST

The PCM cannot detect leaks or restrictions in the vacuum circuits of vacuum assisted engine control system devices. However, these could cause the PCM to store a MAP sensor diagnostic trouble code and cause a high idle condition.

PCM SYSTEM GROUND

The PCM cannot determine a poor system ground. However, one or more diagnostic trouble codes may be generated as a result of this condition. The module should be mounted to the body at all times, also during diagnostic.

PCM CONNECTOR ENGAGEMENT

The PCM may not be able to determine spread or damaged connector pins. However, it might store diagnostic trouble codes as a result of spread connector pins.

The PCM compares input signal voltages from each input device with established high and low limits for the device. If the input voltage is not within limits and other criteria are met, the PCM stores a diagnostic trouble code in memory. Other diagnostic trouble code criteria might include engine RPM limits or input voltages from other sensors or switches that must be present before verifying a diagnostic trouble code condition.

OBD II MONITOR INFORMATION

OBD II MONITOR RUN PROCESS

The following procedure has been established to assist Chrysler Dealer Technicians in the field with enabling and running OBD II Monitors. The order listed in the following procedure is intended to allow the technician to effectively complete each monitor and to set the CARB Readiness Status in the least time possible.

Note. Once the monitor run process has begun, do not turn off the ignition. By turning the ignition key off, monitor enabling conditions will be lost. NVLD Monitor runs after key off. By performing a Battery Disconnect, or Selecting Erase DTCs, the CARB Readiness and all additional OBD II information will be cleared.

MONITOR PRELIMINARY CHECKS

1. Plug a scan tool into the vehicle's Data Link Connector (DLC).
2. Turn the ignition, KEY ON - ENGINE OFF. Watch for MIL lamp illumination during the bulb check. MIL lamp must have illuminated, if not, repair MIL lamp.
3. Using a scan tool check for Powertrain related DTCs.

1. Verify that No Emissions Related DTCs are Present.
2. * If an Emissions DTC is Present, the OBD II Monitors may not run and the CARB Readiness will not update.
3. The Emissions related DTC, will need to be repaired, then cleared. By clearing DTCs, the OBD Monitors will need to be run and completed to set the CARB Readiness Status.

Using the scan tool check the CARB Readiness Status.

Do all the CARB Readiness Status Locations read YES?.

1. *YES, then all monitors have been completed and this vehicle is ready to be I/M or Emission Tested.
2. *NO, then the following procedure needs to be followed to run/complete all available monitors.

Note. Only the monitors, which are not YES in the CARB Readiness Status, need to be completed. Specific criteria need to be met for each monitor. The most efficient order to run the monitors has been outlined below, including suggestions to aid the process.

EVAPORATIVE EMISSION SYSTEM LEAK DETECTION WITH PURGE MONITOR

This monitor requires a cool down cycle, usually an overnight soak for at least 8 hours without the engine running. The ambient temperature must decrease overnight - parking the vehicle outside is advised. To run this test the fuel level must be between 15-85% full. For the monitor run conditions select the EVAP MON PRE-TEST in the scan tool, OBD II Monitors Menu. The Purge monitor will run if the small leak test reports a pass. Criteria for EVAP monitor

1. Engine off time greater than @ one hour.
2. Fuel Level between 15% and 85 %.
3. Start Up ECT and IAT within 10° C (18° F).
4. Vehicle started and run until Purge Monitor reports a result.

Note. If the vehicle does not report a result and the conditions where correct. It may take up to two weeks to fail the small leak monitor. DO NOT use this test to attempt to determine a fault. Use the appropriate service information procedure for finding a small leak. If there are no faults and the conditions are correct this test will run and report a pass. Note the Small leak test can find leaks less than 10 thousands of an inch. If a small leak is present it takes approximately one week of normal driving to report a failure.

CATALYST / O2 MONITOR

With NGC, Catalyst and O2 Monitor information are acquired and processed at the same time. Most vehicles will need to be driven at highway speed (< 50 mph) for a few minutes. Some vehicles run the monitor at idle in drive. If the vehicle is equipped with a manual transmission, using 4th gear may assist in meeting the monitor running criteria. For the monitor run conditions, select the BANK 1 CAT MON PRE-TEST in the scan tool, OBD II Monitors Menu.

EGR MONITOR

The EGR monitor now runs in a closed throttle decel or at idle on a warm vehicle. However, it is necessary to maintain the TPS, Map and RPM ranges to allow the monitor to complete itself. For the monitor run conditions, select the EGR PRE-TEST in the scan tool, OBD II Monitors Menu.

O2 SENSOR HEATER MONITOR

This monitor is now continuously running once the heaters are energized. Pass information will be processed at power down. For the monitor run conditions, select the O2S HEATER MON PRE-TEST in the scan tool, OBD II Monitors Menu.

MIS-FIRE MONITOR

The NGC Misfire Monitor is a continuous two-trip monitor. The monitor uses two different tests/counters

Note. The Adaptive Numerator must be learned before the PCM will run the Mis-Fire Monitor. The PCM updates the Adaptive Numerator at every key-ON, and is relearned after battery disconnect. The Misfire Monitor will not run until the Adaptive Numerator has updated since the last battery disconnect. If the Adaptive Numerator is equal to the default value then the PCM knows that the Adaptive Numerator has not been learned and does not permit the Misfire Monitor to run. If the Adaptive Numerator exceeds a calibrated percentage, the PCM sets a DTC for CKP NOT LEARNED and illuminates the MIL.

1. 200 Revolution Counter - Looks for misfire that can cause immediate catalyst damage.
2. 1000 Revolution Counter - Looks for misfire that can cause emissions to increase 1.5 times the Federal Test Procedure (FTP) standards. This test must also identify misfire percentages that might cause a "durability demonstration vehicle" to fail an Inspection and Maintenance Program tailpipe emissions test.

TORQUE SPECIFICATIONS

The EVAP vapor canister is located in the left rear quarter panel behind the left rear wheelhouse splash shield.

Scheme 1

1. ESIM fresh air filter hose (1).
2. ESIM electrical connector (2).
3. Evaporative System Integrity Monitor (ESIM) (3).
4. EVAP Vapor purge line (4).
5. Fuel tank vapor line (5).

Scheme 2

The vapor canister is mounted to a V-Slot bracket and does not require any fasteners.

OPERATION

The Evaporative System Vapor Canister is filled with granules of an activated carbon mixture. Fuel vapors entering the EVAP canister is absorbed by the charcoal granules.

Fuel tank pressure vents into the EVAP canister. Fuel vapors are temporarily held in the canister until they can be drawn into the intake manifold. The duty cycle EVAP canister purge solenoid allows the EVAP canister to be purged at predetermined times and at certain engine operating conditions.

REMOVAL

Scheme 3

The Evaporative System Integrity Monitor (ESIM) (3) is very similar to the NVLD. However, the design of the ESIM has been simplified and unlike the NVLD the ESIM does not require a solenoid. The ESIM mounts directly to the EVAP vapor canister, eliminating the need for a mounting bracket. The EVAP vapor canister is located in the left rear quarter panel behind the left rear wheelhouse splash shield.

Scheme 4

1. Disconnect and isolate the negative battery cable (2).
2. Remove the fuel tank filler cap.
3. Raise and support vehicle.
4. Remove left rear wheel and tire.
5. Remove the left rear wheelhouse splash shield. Refer to «SHIELD, SPLASH, WHEELHOUSE , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/gauges-instrument-panels/#body-interior-exterior) . NOTE: When removing the fresh air hose, remove the hose at the fresh air filter first, this will eliminate the risk of breaking the nipple from the ESIM during removal.
6. Carefully remove the ESIM fresh air hose (1) at the fresh air filter.
7. Disconnect the electrical connector (2) at the ESIM.
8. Rotate the ESIM (3) counter-clockwise about 70 degrees and remove.
9. Disconnect the vapor purge line (4) quick-connect fitting from the EVAP canister.
10. Disconnect the fuel tank vapor line (5) quick-connect fitting from the EVAP canister. The vapor canister is mounted to a V-Slot bracket and does not require any fasteners.
11. Depress the retaining tab (1) at the back side of the vapor canister and with a lifting motion remove the vapor canister from the V-Slot (2) mounting bracket.

INSTALLATION

The vapor canister is mounted to a V-Slot bracket and does not require any fasteners.

1. Position the vapor canister to the V-Slot (2) mounting bracket and slide the canister downward into the V-Slot until the retaining tab (1) clicks/locks in place. NOTE: The vapor/vacuum lines must be firmly connected. Check the vapor/vacuum lines at the EVAP canister for damage or leaks. If a leak is present, a Diagnostic Trouble Code (DTC) may be set.
2. Connect the fuel tank vapor line (5) quick-connect fitting to the EVAP canister.
3. Connect the vapor purge line (4) quick-connect fitting to the EVAP canister.
4. Position the ESIM (3) to the EVAP canister and rotate clockwise about 70 degrees and lock in place.
5. Connect the electrical connector (2) at the ESIM.
6. Carefully install the ESIM fresh air hose (1) at the fresh air filter.
7. Install the left rear wheelhouse splash shield. Refer to «SHIELD, SPLASH, WHEELHOUSE , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/gauges-instrument-panels/#body-interior-exterior) .
8. Install left rear wheel and tire.
9. Lower the vehicle.
10. Connect the negative battery cable (2).
11. Install the fuel tank filler cap.
12. Start the engine and check for leaks.

The plastic fuel fill cap is a threaded/quarter turn onto the end of the fuel fill tube. Its purpose is to retain vapors and fuel in the fuel tank.

The loss of any fuel vapor out of fuel filler tube is prevented by the use of pressure-vacuum fuel fill cap. Relief valves inside the cap will release fuel tank pressure at predetermined pressures. Fuel tank vacuum will also be released at predetermined values. This cap must be replaced by a similar unit if replacement is necessary. This is in order for the system to remain effective.

If replacement of the 1/4 turn fuel tank filler tube cap is necessary, it must be replaced with an identical cap to be sure of correct system operation.

A vacuum schematic for emission related items can be found on the vehicles VECI label. Refer to Vehicle Emission Control Information (VECI) Label for label location.

The ORVR (On-Board Refueling Vapor Recovery) system consists of a unique fuel tank, flow management valve, fluid control valve, one-way check valve and vapor canister.

The ORVR (On-Board Refueling Vapor Recovery) system is used to remove excess fuel tank vapors. This is done while the vehicle is being refueled.

Fuel flowing into the fuel filler tube (approx. 1" I.D.) creates an aspiration effect drawing air into the fuel fill tube. During refueling, the fuel tank is vented to the EVAP canister to capture escaping vapors. With air flowing into the filler tube, there are no fuel vapors escaping to the atmosphere. Once the refueling vapors are captured by the EVAP canister, the vehicle's computer controlled purge system draws vapor out of the canister for the engine to burn. The vapor flow is metered by the purge solenoid so that there is no, or minimal impact on driveability or tailpipe emissions.

As fuel starts to flow through the fuel fill tube, it opens the normally closed check valve and enters the fuel tank. Vapor or air is expelled from the tank through the control valve and on to the vapor canister. Vapor is absorbed in the EVAP canister until vapor flow in the lines stops. This stoppage occurs following fuel shut-off, or by having the fuel level in the tank rise high enough to close the control valve. This control valve contains a float that rises to seal the large diameter vent path to the EVAP canister. At this point in the refueling process, fuel tank pressure increases, the check valve closes (preventing liquid fuel from spiting back at the operator), and fuel then rises up the fuel filler tube to shut off the dispensing nozzle.

Scheme 5

The EVAP canister purge solenoid is located in the engine compartment attached to a bracket mounted on the left strut tower.

The Powertrain Control Module (PCM) operates the EVAP canister purge solenoid depending upon engine operating conditions.

The Powertrain Control Module (PCM) operates the solenoid.

During the cold start warm-up period and the hot start time delay, the PCM does not energize the solenoid. When de-energized, no vapors are purged. The PCM de-energizes the solenoid during open loop operation.

The engine enters closed loop operation after it reaches a specified temperature and the time delay ends. During closed loop operation, the PCM energizes and de-energizes the solenoid 5 or 10 times per second, depending upon operating conditions. The PCM varies the vapor flow rate by changing solenoid pulse width. Pulse width is the amount of time the solenoid energizes. The PCM adjusts solenoid pulse width based on engine operating condition.

The EVAP canister purge solenoid (1) is located in the engine compartment attached to a bracket mounted on the left strut tower.

1. Disconnect the vapor/vacuum lines (1, 2) at the canister purge solenoid.
2. Disconnect the electrical connector (3) at the canister purge solenoid.
3. Depress the retaining tab (4), slide the canister purge solenoid forward and remove solenoid from the mounting bracket.

1. Slide the EVAP canister purge solenoid onto the mounting bracket until the locking tab (4) click/locks into position.
2. Connect the electrical connector (3) at the canister purge solenoid.
3. Connect the vacuum/vapor lines (2, 1) at the canister purge solenoid.

Scheme 6

The Evaporative System consists of the following components

1. Purge Solenoid (1)
2. Intake Manifold (2)
3. Fuel Tank (3)
4. ORVR Control Valve (4)
5. ESIM (5)
6. Vapor Canister (6)
7. Fresh Air Filter (7)
8. Gas Cap (8)
9. Throttle Body (9)

The ESIM (Evaporative System Integrity Monitor) is very similar to the NVLD. However, the design of the ESIM has been simplified and unlike the NVLD the ESIM does not require a solenoid. The ESIM mounts directly to the canister, eliminating the need for a mounting bracket. It is critical that the ESIM is mounted vertically. On vehicles where the canister is mounted on an angle, the ESIM requires an adaptor to maintain a vertical position. When the ESIM is installed vertically, the electrical connector is in the 3 o'clock position.

Scheme 7

The ESIM consists of the following components

1. ESIM Housing (1)
2. Diaphragm (2)
3. Switch (3)
4. Cover (4)
5. Small Check Valve (5)
6. Large Check Valve (6)

There is one large weight and one small weight check valve in the ESIM assembly. A seal is attached at the end of each weighted check valve. The large weight check valve seals for pressure. The small weight check valve seals for vacuum. The weighted check valves are contained within the ESIM housing.

The ESIM (Evaporative System Integrity Monitor), while physically different than the NVLD system, performs the same basic function as the NVLD does - controlling evaporative emissions. The ESIM has been simplified because the solenoid used on the NVLD is not used on the ESIM.

Scheme 8

The ESIM consists of housing, two check valves (1, 4) (sometimes referred to as weights), a diaphragm (3), a switch and a cover.

During refueling, pressure is built up in the evaporative system. When pressure reaches approximately.5 inches of water, the large check valve (1) unseats and pressure vents to the fresh air filter.

Conversely, when the system cools, and the resulting vacuum lifts the small check valve from its seat and allows fresh air to enter the system through the fresh air inlet (2) and relieves the vacuum condition. When a calibrated amount of vacuum is achieved in the evaporative system, the diaphragm is pulled inward, pushing on the spring and closing the contacts.

The ESIM conducts test on the evaporative system as follows: An engine off, non-intrusive test for small leaks and an engine running, intrusive test for medium/large leaks.

The ESIM weights seal the evaporative system during engine off conditions. If the evaporative system is sealed, it will be pulled into a vacuum, either due to the cool down from operating temperature or diurnal ambient temperature cycling. When the vacuum in the system exceeds about 1" H20, the vacuum switch closes. The switch closure sends a signal to the PCM. In order to pass the non-intrusive small leak test, the ESIM switch must close within a calculated amount of time and within a specified amount of key-off events.

If the ESIM switch does not close as specified, the test is considered inconclusive and the intrusive engine running test will be run during the next key-on cycle. This intrusive test will run on the next cold engine running condition.

Conditions for running the intrusive test are

1. After the vehicle is started, the engine coolant temperature must be within 50° F (10° C) of ambient to indicate a cold start.
2. The fuel level must be between 12% and 88%.
3. The engine must be in closed loop.
4. Manifold vacuum must be greater than a minimum specified value.
5. Ambient temperature must be between 39° F and 98° F (4° C and 37° C) and the elevation level must be below 8500 feet (2591 meters).

The test is accomplished by the PCM activating the purge solenoid to create a vacuum in the evaporative system. The PCM then measures the amount of time it takes for the vacuum to dissipate. This is known as the vacuum decay method. If the switch opens quickly a large leak is recorded. If the switch opens after a predetermined amount of time, then the small leak matures. If the switch does not close, then a general evaporative failure is recorded. The purge monitor tests the integrity of the hose attached between the purge valve and throttle body/intake. The purge monitor is a two stage test and it runs only after the evaporative system passes the small leak test.

Even when all of the thresholds are met, a small leak won't be recorded until after the medium/large leak monitor has been run. This is accomplished by the PCM activating the purge solenoid to create a vacuum in the evaporative system. The PCM then measures the amount of time it takes for the vacuum to dissipate. This is known as the vacuum decay method. If the switch opens quickly a large leak is recorded. If the switch opens after a predetermined amount of time, then the small leak matures. If the medium/large leak test runs and the ESIM switch doesn't close, a general evaporative test is run. The purge solenoid is activated for approximately 10 seconds, increasing the amount of vacuum in the system. If the ESIM switch closes after the extended purge activation, a large leak fault is generated. If the switch doesn't close, a general evaporative system fault is generated.

The purge monitor tests the integrity of the hose attached between the purge valve and throttle body/intake. The purge monitor is a two stage test and it runs only after the evaporative system passes the small leak test.

Stage one of the purge monitor is non-intrusive. The PCM monitors the purge vapor ratio. If the ratio is above a calibrated specification, the monitor passes. Stage two is an intrusive test and it runs only if stage one fails. During the stage two test, the PCM commands the purge solenoid to flow at a specified rate to force the purge vapor ratio to update. The vapor ratio is compared to a calibrated specification and if it is less than specified, a one-trip failure is recorded.

The ESIM switch stuck closed monitor checks to see if the switch is stuck closed. This is a power down test that runs at key-off; when the PCM sees 0 RPM's, the purge solenoid is energized for a maximum of 30 seconds, venting any vacuum trapped in the evaporative system. If the switch opens or was open before the test began, the monitor passes. If the switch doesn't open, the monitor fails. This is a two-trip MIL. The star scan tool can be used to force the ESIM switch stick closed monitor to run.

The PCM also uses the ESIM to detect a loose or missing gas cap. The PCM controller looks for a change in the fuel level (25% minimum) and then gas cap is loose or missing. If a medium/large leak is detected, a loose gas cap light illuminates and a pending one-trip fault code is set. On the PCM, this is a three-trip fault before the code matures

The Evaporative System Integrity Monitor (ESIM) (3) is very similar to the NVLD. However, the design of the ESIM has been simplified and unlike the NVLD the ESIM does not require a solenoid. The ESIM mounts directly to the EVAP vapor canister, eliminating the need for a mounting bracket. The EVAP vapor canister is located in the left rear quarter panel behind the left rear wheelhouse splash shield.

Scheme 9

1. Disconnect and isolate the negative battery cable (2).
2. Remove the fuel tank filler cap.
3. Raise and support vehicle.
4. Remove left rear wheel and tire.
5. Remove the left rear wheelhouse splash shield. Refer to «SHIELD, SPLASH, WHEELHOUSE , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/gauges-instrument-panels/#body-interior-exterior) . NOTE: When removing the fresh air hose, remove the hose at the fresh air filter first, this will eliminate the risk of breaking the nipple from the ESIM during removal.
6. Carefully remove the ESIM fresh air hose (1) at the fresh air filter.
7. Disconnect the electrical connector (2) at the ESIM.
8. A lock tab (see arrow) is used on the back of the switch. Push the lock tab towards ESIM switch while rotating counterclockwise 1/4 turn for removal. The fresh air lines and hoses from the ESIM must have a clear opening to the atmosphere. Check the fresh air lines, including the fresh air filter, for obstructions or restrictions at the ESIM. If a restriction is present, the system will not allow free flow passage of clean air, and an early shut off of the fuel fill nozzle may occur during refueling.
9. Clean any dirt from ESIM switch, lines and EVAP canister opening.
10. Inspect the ESIM O-ring, replace if necessary.

1. A lock tab (see arrow) is used on the back of the switch. Position the ESIM switch into the EVAP canister and rotate switch until the electrical connector is in 3 O'clock position and the locking tab locks into position.
2. Connect the ESIM fresh air hose (1) at the fresh air filter.
3. Connect the electrical connector (2) at the ESIM.
4. Install the left rear wheelhouse splash shield. Refer to «SHIELD, SPLASH, WHEELHOUSE , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/gauges-instrument-panels/#body-interior-exterior) .
5. Install left rear wheel and tire.
6. Lower the vehicle.
7. Connect the negative battery cable (2).
8. Install the fuel tank filler cap.
9. Start the engine and check for leaks.

Scheme 10

Scheme 11

1. Remove the hose (1) from the PCV valve (2).
2. Remove the three screws (2) and the PCV valve (1) from the right cylinder head cover.

INSTALLATION - PCV VALVE

1. Clean and inspect the sealing surfaces of the PCV valve and cylinder head cover. The seal can be reused provided it is free of cuts or tears.
2. Install the PCV valve seal in the cylinder head cover.
3. Install the PCV valve (1) with three screws (2). Tighten the screws to 4 N.m (35 in. lbs.).
4. Install the PCV hose (1) between the upper intake manifold and the PCV valve (2).

Scheme 12

The PCV valve (1) is located at the top right rear of the intake manifold.

Scheme 13

1. The PCV valve is sealed to the intake manifold with two O-rings (2).
2. Remove the PCV valve by rotating counter-clockwise 90 degrees until the locating tabs (3) have been released.
3. Pull the PCV valve straight up and remove from the intake manifold.
4. Check the condition of the two PCV valve O-rings (2), replace if necessary.

1. Check the condition of the two PCV valve O-rings (2), replace if necessary.
2. Clean the PCV valve mounting surface of the intake manifold opening.
3. Apply engine oil to the two O-rings (2) on the PCV valve.
4. Position the PCV valve (1) into intake manifold and rotate 90 degrees clockwise until the locating tabs are locked in place.

GLOSSARY OF TERMS

The following procedure has been established to assist technicians in the field with enabling and running OBD II Monitors. The order listed in the following procedure is intended to allow the technician to effectively complete each monitor and to set the CARB Readiness Status in the least time possible.

Note. Once the monitor run process has begun, do not turn off the ignition. By turning the ignition key off, monitor enabling conditions will be lost. EVAP Monitor runs after key off. By performing a Battery Disconnect, or Selecting Erase DTCs, the CARB Readiness and all additional OBD II information will be cleared.

1. Plug a scan tool into the vehicle's Data Link Connector (DLC).
2. Turn the ignition, KEY ON - ENGINE OFF. Watch for the MIL lamp illumination during the bulb check. MIL lamp must illuminate, if not, repair MIL lamp.
3. Using a scan tool check for Powertrain related DTCs.

1. Verify that No Emissions Related DTCs are Present. If an Emissions DTC is Present, the OBD II Monitors may not run and the CARB Readiness will not update.
2. The Emissions related DTC, will need to be repaired, then cleared. By clearing DTCs, the OBD Monitors will need to be run and completed to set the CARB Readiness Status.

Using the scan tool check the CARB Readiness Status.

Do all the CARB Readiness Status Locations read YES?

1. YES - all monitors have been completed and this vehicle is ready to be I/M or Emission Tested.
2. NO - then the following procedure needs to be followed to run/complete all available monitors.

Note. Only the monitors, which are not YES in the CARB Readiness Status, need to be completed. Specific criteria need to be met for each monitor. The most efficient order to run the monitors has been outlined below, including suggestions to aid the process.

This monitor requires a cool down cycle, usually an overnight soak for at least 8 hours without the engine running. The ambient temperature must decrease overnight - parking the vehicle outside is advised. To run this test the fuel level must be between 15-85% full. Criteria for EVAP monitor

1. Engine off time greater than one hour.
2. Fuel Level between 15% and 85%.
3. Start Up ECT and IAT within 10°C (18°F).
4. Vehicle started and run until Purge Monitor reports a result.

Note. If the vehicle does not report a result and the conditions where correct. It may take up to two weeks to fail the small leak monitor. DO NOT use this test to attempt to determine a fault. Use the appropriate service information procedure for finding a small leak. If there are no faults and the conditions are correct this test will run and report a pass. Note the Small leak test can find leaks less than 10 thousands of an inch. If a small leak is present it takes approximately one week of normal driving to report a failure.

The Catalyst and O2 Monitor information are acquired and processed at the same time. Most vehicles will need to be driven at highway speed (less than 50 mph) (73km/h) for a few minutes. Some vehicles run the monitor at idle in drive. If the vehicle is equipped with a manual transmission, using 4th gear may assist in meeting the monitor running criteria.

1. Engine RPM between 1200 to 3000.
2. Engine temperature greater than 70°C (158°F)
3. Engine run time greater than 92 seconds
4. MAP between 10 - 20 kPa (7.5 - 15 Hg)
5. Vehicle speed between 20 - 70 mph (29-103 km/h)

After the vehicle has reached the below conditions and during a throttle decel the EGR monitor will run.

1. Engine RPM between 1375 - 2500
2. Engine temperature greater than 70°C (158°F)
3. Engine run time greater than 125 seconds
4. Vehicle speed between 25 - 70 mph (37-103 km/h)

This monitor is now continuously running once the heaters are energized. Pass information will be processed at power down.

The Misfire Monitor is a continuous two-trip monitor. The monitor uses two different tests/counters

Note. The Adaptive Numerator must be learned before the PCM will run the Mis-Fire Monitor. The PCM updates the Adaptive Numerator at every key-ON, and is relearned after battery disconnect. The Misfire Monitor will not run until the Adaptive Numerator has updated since the last battery disconnect. If the Adaptive Numerator is equal to the default value then the PCM knows that the Adaptive Numerator has not been learned and does not permit the Misfire Monitor to run. If the Adaptive Numerator exceeds a calibrated percentage, the PCM sets a DTC for CKP NOT LEARNED and illuminates the MIL.

1. 200 Revolution Counter - Looks for misfire that can cause immediate catalyst damage.
2. 1000 Revolution Counter - Looks for misfire that can cause emissions to increase 1.5 times the Federal Test Procedure (FTP) standards. This test must also identify misfire percentages that might cause a "durability demonstration vehicle" to fail an Inspection and Maintenance Program tailpipe emissions test.

Scheme 14

The EGR Cooler Vacuum Solenoid (1) is located on the intake manifold next to the thermostat housing.

REMOVAL - EGR VACUUM BYPASS SOLENOID

1. Disconnect the negative battery cable.
2. Remove the engine cover.
3. Disconnect EGR vacuum bypass harness connector.
4. Disconnect vacuum lines (3).
5. Remove bolts (2) and the EGR vacuum bypass solenoid (1).

INSTALLATION - EGR VACUUM BYPASS SOLENOID

1. Install the EGR vacuum bypass solenoid (1). Tighten bolts (2) to 9 N.m (80 in. lbs.).
2. Connect vacuum lines (3).
3. Connect EGR vacuum bypass harness connector.
4. Install the engine cover
5. Connect the negative battery cable.

Scheme 15

1. Disconnect the negative battery cable.
2. Remove engine cover.
3. Disconnect the EGR valve harness connector (2).
4. Remove retaining bolts (1) the EGR valve, and discard the gasket.

Scheme 16

1. Clean EGR valve sealing surfaces.
2. Install a new gasket (1) onto the EGR valve.
3. Install the EGR valve and securely tighten bolts (1).
4. Connect the EGR valve harness connector (2).
5. Install engine cover.
6. Connect the negative battery cable.

Scheme 17

Scheme 18

1. Remove the engine cover.
2. Loosen clamp bolts (1 and 3) and remove the EGR tube (2).
3. Remove and discard gaskets.
4. If necessary, remove fasteners (1) the EGR tube adapter pipe (2).
5. Remove and discard gasket.

Scheme 19

Scheme 20

1. Clean all gasket sealing areas.
2. If removed, install a new EGR tube adapter pipe gasket (1).
3. If removed, install the EGR tube adapter pipe (2) and securely tighten fasteners (1).
4. Using a new gaskets (1 and 5), install the EGR tube (3) and tighten clamps (2 and 4) finger tight.
5. Tighten clamp bolts (1 and 3) to 4 N.m (35 in. lbs.).
6. Install the engine cover.

Scheme 21

Scheme 22

Scheme 23

Scheme 24

1. Disconnect the negative battery cable.
2. Remove the front skid plate. Refer to «PLATE, SKID, FRONT , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/frames-subframes-crossmembers/#frame-and-bumpers) .
3. Drain the cooling system. Refer to «STANDARD PROCEDURE»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) .
4. Lower the vehicle.
5. Remove the engine cover.
6. Disconnect the EGR valve harness connector (2).
7. Disconnect the EGR cooler vacuum bypass hose (1).
8. Remove the EGR tube. Refer to «TUBE, EXHAUST GAS RECIRCULATION (EGR) , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#emissions-control) .
9. Remove the turbocharger-to-EGR cooler tube clamp (1).
10. Remove bolt (3) at the rear EGR cooler bypass valve support bracket (2).
11. Remove bolts (1) and the EGR and cooler assembly (2).
12. Remove and discard O-ring seals (3, 5-6).

INSTALLATION - EGR COOLER

1. Clean the O-ring sealing surface.
2. Install new O-ring seals (6) onto the EGR cooler and mounting bracket (7).
3. Lubricate and install new lower O-ring seals (5) onto spacers (4) and install spacers into EGR cooler mounting bracket (7).
4. Lubricate and install new upper O-ring seals (3) onto EGR cooler (2).
5. Install the EGR and cooler assembly (2). Tighten bolts (1) to 25 N.m (18 ft. lbs.).
6. Install bolt (3) at the rear EGR cooler bypass valve support bracket (2) and tighten to 25 N.m (18 ft. lbs.).
7. Using a new gasket the turbocharger-to-EGR cooler tube and securely tighten clamp (1).
8. Install the EGR tube. Refer to «TUBE, EXHAUST GAS RECIRCULATION (EGR) , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#emissions-control) .
9. Disconnect the EGR cooler vacuum bypass hose (1).
10. Connect the EGR valve harness connector (2).
11. Install the engine cover.
12. Fill the cooling system. Refer to «STANDARD PROCEDURE»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) .
13. Install the front skid plate. Refer to «PLATE, SKID, FRONT , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/frames-subframes-crossmembers/#frame-and-bumpers) .
14. Lower the vehicle.
15. Connect the negative battery cable.

Scheme 25

The Exhaust Gas Recirculation (EGR) Air Flow Control Valve (2) is attached to the intake manifold. The EGR Air Flow Control Valve is controlled by the Powertrain Control Module (PCM). Refer to the appropriate engine diagnostic procedures for DTCs related to the EGR Airflow Control Valve.

OPERATION - EGR AIR FLOW CONTROL VALVE

The Exhaust Gas Recirculation (EGR) Air Flow Control Valve adjusts the flow of fresh air into the engine during EGR operation. A signal from the Powertrain Control Module (PCM) controls the operation of the EGR throttle valve. The position at which the PCM will set the valve depends on the blended quantity of exhaust gas that needs to be recirculated into the engine in order for the exhaust gas to remain with the target emission level, which the PCM calculates based on input received from the oxygen sensors. When not actuated, the EGR throttle valve is in the open position.

REMOVAL - EGR AIR FLOW CONTROL VALVE

1. Disconnect the negative battery cable.
2. Remove the engine cover.
3. Disconnect air tube from the EGR air flow control valve.
4. Disconnect the EGR Airflow Valve harness connector.
5. Remove the high pressure fuel tube support bracket bolt (1).
6. Remove the four bolts (3) and the EGR airflow control valve (2).

Scheme 26

Scheme 27

1. Clean all gasket sealing surfaces.
2. Install a new O-ring seal onto the air inlet housing (2).
3. Install a new O-ring seal (1) onto the intake manifold.
4. Install the EGR airflow control valve (2). Tighten the four bolts (3) to (9 N.m 80 in. lbs.).
5. Install the high pressure fuel tube support bracket bolt (1) and tighten to 11 N.m (97 in. lbs.).
6. Connect the EGR airflow control valve harness connector.
7. Connect the air tube to the EGR air flow control valve.
8. Install the engine cover.
9. Connect the negative battery cable.

Scheme 28

1. Disconnect the negative battery cable.
2. Remove the engine cover.
3. Disconnect the breather hose at left upper timing cover.
4. Disconnect the CCV hose heater harness connector (1).
5. Disconnect the CCV hose (2) from intake air tube (3).

INSTALLATION - CRANKCASE VENT HOSE

1. Connect the CCV hose (2) from intake air tube (3).
2. Connect the CCV hose heater harness connector (1).
3. Connect the breather hose at timing cover.
4. Install the engine cover.
5. Connect the negative battery cable.

Scheme 29

Scheme 30

1. Remove the negative battery cable.
2. Remove the engine cover (1).
3. Disconnect the crankcase breather hose (1).
4. Disconnect the crankcase vent heater wire harness connector (4).
5. Carefully pull out the crankcase vent heater (2) from turbo air inlet hose (3).

INSTALLATION - CLOSED CRANKCASE VENT HEATHER

1. Install the crankcase vent heater (2) into turbo air inlet hose (3).
2. Connect the crankcase vent heater wire harness connector (4).
3. Install the crankcase breather hose (1).
4. Install the engine cover (1).
5. Connect the negative battery cable.

See also:
• SHIELD, SPLASH, WHEELHOUSE , REMOVAL
• PLATE, SKID, FRONT , REMOVAL
• STANDARD PROCEDURE
• TUBE, EXHAUST GAS RECIRCULATION (EGR) , REMOVAL