When the variable ground signal is supplied to the
EVM, vacuum from the vacuum pump will be
allowed to pass through the EVM and on to the EGR
valve with a connecting hose.
Exhaust gas recirculation will begin in this order
when:
•
The ECM determines that EGR system opera-
tion is necessary.
•
The engine is running to operate the vacuum
pump.
•
A variable ground signal is supplied to the EVM.
•
Variable vacuum passes through the EVM to the
EGR valve.
•
The inlet seat (poppet valve) at the bottom of
the EGR valve opens to dilute and recirculate
exhaust gas back into the intake manifold.
The EGR system will be shut down by the ECM
after 60 seconds of continuous engine idling to
improve idle quality.
DIAGNOSIS AND TESTING
EGR GAS FLOW TEST
Refer to the 2000 XJ Diesel Powertrain Diagnostic
Manual for complete test procedure.
EGR SOLENOID TEST
VACUUM TEST
With the engine running, disconnect the vacuum
supply line at the fitting on the Electric Vacuum
Modulator (EVM). Vacuum should be no less than 20
inches. If vacuum is lower, check for leaks in vacuum
supply line. If leaks cannot be found, check for low
vacuum at vacuum pump.
REMOVAL AND INSTALLATION
EGR VALVE
REMOVAL
(1) Disconnect vacuum line at EGR valve vacuum
supply fitting.
(2) Loosen the tube fitting at exhaust manifold end
of EGR tube.
(3) Remove the two bolts retaining the EGR tube
to the EGR valve and remove the EGR tube.
(4) Remove the two bolts retaining the EGR valve
to the intake manifold elbow and remove EGR valve.
(5) Discard both of the old EGR mounting gaskets.
INSTALLATION
(1) Clean the intake manifold of any old gasket
material.
(2) Clean the end of EGR tube of any old gasket
material.
(3) Position the EGR valve and new gasket to the
intake manifold elbow.
(4) Install two EGR valve mounting bolts. Do not
tighten bolts at this time.
(5) Position new gasket between EGR valve and
EGR tube.
(6) Install two EGR tube bolts. Tighten all four
mounting bolts to 23 N·m (204 in. lbs.).
(7) Tighten EGR tube fitting at exhaust manifold.
(8) Connect vacuum line to EGR valve.
EGR TUBE
The EGR tube connects the EGR valve to the rear
of the exhaust manifold.
REMOVAL
(1) Remove two EGR tube mounting bolts at EGR
valve end of tube.
(2) Loosen fitting at exhaust manifold end of tube.
(3) Remove EGR tube and discard old gasket.
(4) Clean gasket mating surfaces and EGR tube
flange gasket surfaces.
(5) Check for signs of leakage or cracked surfaces
at both ends of tube, exhaust manifold and EGR
valve.
INSTALLATION
(1) Install a new gasket to EGR valve end of EGR
tube.
(2) Position EGR tube to engine.
(3) Loosely tighten fitting at exhaust manifold end
of tube.
(4) Install 2 mounting bolts at EGR valve end of
tube. Tighten bolts to 23 N·m (204 in. lbs.) torque.
(5) Tighten fitting at exhaust manifold end of tube.
Fig. 2 Internal Vacuum Pump
1 – INTERNAL VACUUM PUMP AND DRIVE GEAR
XJ
EMISSION CONTROL SYSTEM
25 - 7
DESCRIPTION AND OPERATION (Continued)
Summary of Contents for 200 Cherokee
Page 5: ...FASTENER IDENTIFICATION 4 INTRODUCTION XJ DESCRIPTION AND OPERATION Continued ...
Page 6: ...FASTENER STRENGTH XJ INTRODUCTION 5 DESCRIPTION AND OPERATION Continued ...
Page 8: ...METRIC CONVERSION CHART XJ INTRODUCTION 7 DESCRIPTION AND OPERATION Continued ...
Page 9: ...TORQUE SPECIFICATIONS 8 INTRODUCTION XJ DESCRIPTION AND OPERATION Continued ...
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Page 107: ...Fig 105 Gear Tooth Contact Patterns 3 60 TUBE 181 AND 186 FBI AXLE XJ ADJUSTMENTS Continued ...
Page 111: ...Installer D 144 Installer W 262 3 64 TUBE 181 AND 186 FBI AXLE XJ SPECIAL TOOLS Continued ...
Page 145: ...Fig 79 Gear Tooth Contact Patterns 3 98 194 RBI AXLE XJ ADJUSTMENTS Continued ...
Page 177: ...Fig 59 Gear Tooth Contact Patterns 3 130 8 1 4 REAR AXLE XJ ADJUSTMENTS Continued ...
Page 230: ...Fig 8 Clutch Components And Inspection XJ CLUTCH 6 5 DIAGNOSIS AND TESTING Continued ...
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Page 484: ...SPECIAL TOOLS HEADLAMP ALIGNMENT Headlamp Aiming Kit C 4466 A XJ LAMPS 8L 9 ...
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Page 1072: ...Fig 16 2 5L Engine XJ 8W 90 CONNECTOR LOCATIONS 8W 90 25 DESCRIPTION AND OPERATION Continued ...
Page 1073: ...Fig 17 4 0L Engine 8W 90 26 8W 90 CONNECTOR LOCATIONS XJ DESCRIPTION AND OPERATION Continued ...
Page 1074: ...Fig 18 4 0L Engine XJ 8W 90 CONNECTOR LOCATIONS 8W 90 27 DESCRIPTION AND OPERATION Continued ...
Page 1087: ...Fig 31 Liftgate 8W 90 40 8W 90 CONNECTOR LOCATIONS XJ DESCRIPTION AND OPERATION Continued ...
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Page 1331: ...Fig 6 Frame Dimensions 13 8 FRAME AND BUMPERS XJ SPECIFICATIONS Continued ...
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Page 1912: ...Fig 3 Hood Components XJ BODY 23 25 REMOVAL AND INSTALLATION Continued ...
Page 1955: ...WELD LOCATIONS UPPER COWL 23 68 BODY XJ SPECIFICATIONS Continued ...
Page 1956: ...UPPER COWL XJ BODY 23 69 SPECIFICATIONS Continued ...
Page 1957: ...COWL 23 70 BODY XJ SPECIFICATIONS Continued ...
Page 1958: ...A PILLAR XJ BODY 23 71 SPECIFICATIONS Continued ...
Page 1959: ...A PILLAR 23 72 BODY XJ SPECIFICATIONS Continued ...
Page 1960: ...A PILLAR XJ BODY 23 73 SPECIFICATIONS Continued ...
Page 1961: ...A PILLAR 23 74 BODY XJ SPECIFICATIONS Continued ...
Page 1962: ...B PILLAR XJ BODY 23 75 SPECIFICATIONS Continued ...
Page 1963: ...D PILLAR 23 76 BODY XJ SPECIFICATIONS Continued ...
Page 1964: ...FUEL FILLER OPENING XJ BODY 23 77 SPECIFICATIONS Continued ...
Page 1965: ...CARGO AREA FLOOR PAN 23 78 BODY XJ SPECIFICATIONS Continued ...
Page 1966: ...ROOF AND D PILLAR XJ BODY 23 79 SPECIFICATIONS Continued ...
Page 1967: ...LIFTGATE OPENING 23 80 BODY XJ SPECIFICATIONS Continued ...
Page 1968: ...ROOF XJ BODY 23 81 SPECIFICATIONS Continued ...
Page 1969: ...ROOF 23 82 BODY XJ SPECIFICATIONS Continued ...
Page 1970: ...FRAME RAIL XJ BODY 23 83 SPECIFICATIONS Continued ...
Page 1971: ...FRAME RAIL 23 84 BODY XJ SPECIFICATIONS Continued ...
Page 1972: ...FRAME RAIL XJ BODY 23 85 SPECIFICATIONS Continued ...
Page 1973: ...FRAME RAIL 23 86 BODY XJ SPECIFICATIONS Continued ...
Page 1974: ...REINFORCEMENT XJ BODY 23 87 SPECIFICATIONS Continued ...
Page 1975: ...FRONT INNER FENDER 23 88 BODY XJ SPECIFICATIONS Continued ...
Page 1976: ...FRONT INNER FENDER AND RADIATOR CLOSURE PANEL XJ BODY 23 89 SPECIFICATIONS Continued ...
Page 1977: ...REINFORCEMENT 23 90 BODY XJ SPECIFICATIONS Continued ...
Page 1978: ...FRONT FENDER XJ BODY 23 91 SPECIFICATIONS Continued ...
Page 1979: ...BODY SIDE 23 92 BODY XJ SPECIFICATIONS Continued ...
Page 1980: ...REAR WHEELHOUSE XJ BODY 23 93 SPECIFICATIONS Continued ...
Page 1981: ...REAR INNER WHEELHOUSE 23 94 BODY XJ SPECIFICATIONS Continued ...
Page 1982: ...BODY SIDE XJ BODY 23 95 SPECIFICATIONS Continued ...
Page 1983: ...BODY SIDE 23 96 BODY XJ SPECIFICATIONS Continued ...
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Page 1985: ...BODY SIDE 23 98 BODY XJ SPECIFICATIONS Continued ...
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Page 1987: ...BODY SIDE 23 100 BODY XJ SPECIFICATIONS Continued ...
Page 1988: ...UNDERBODY XJ BODY 23 101 SPECIFICATIONS Continued ...
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Page 1997: ...UNDERBODY 23 110 BODY XJ SPECIFICATIONS Continued ...
Page 1998: ...UNDERBODY XJ BODY 23 111 SPECIFICATIONS Continued ...
Page 1999: ...BODY SEALING LOCATIONS APPLICATION METHODS 23 112 BODY XJ SPECIFICATIONS Continued ...
Page 2000: ...COWL AND DASH PANEL XJ BODY 23 113 SPECIFICATIONS Continued ...
Page 2001: ...DASH PANEL AND FLOOR PAN 23 114 BODY XJ SPECIFICATIONS Continued ...
Page 2002: ...FLOOR PAN XJ BODY 23 115 SPECIFICATIONS Continued ...
Page 2003: ...REAR INNER WHEELHOUSE 23 116 BODY XJ SPECIFICATIONS Continued ...
Page 2004: ...FRONT INNER WHEELHOUSE XJ BODY 23 117 SPECIFICATIONS Continued ...
Page 2005: ...BODY SIDE 23 118 BODY XJ SPECIFICATIONS Continued ...
Page 2006: ...BODY SIDE XJ BODY 23 119 SPECIFICATIONS Continued ...
Page 2007: ...BODY SIDE 23 120 BODY XJ SPECIFICATIONS Continued ...
Page 2008: ...ROOF PANEL XJ BODY 23 121 SPECIFICATIONS Continued ...
Page 2009: ...FUEL FILLER HOUSING 23 122 BODY XJ SPECIFICATIONS Continued ...
Page 2010: ...LIFTGATE OPENING XJ BODY 23 123 SPECIFICATIONS Continued ...
Page 2011: ...STRUCTURAL ADHESIVE LOCATIONS LEFT QUARTER PANEL 23 124 BODY XJ SPECIFICATIONS Continued ...
Page 2012: ...REAR WHEELHOUSE XJ BODY 23 125 SPECIFICATIONS Continued ...
Page 2013: ...ROOF BOWS 23 126 BODY XJ SPECIFICATIONS Continued ...
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