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
and 1600 rpm.
Any component that has an associated limp in will
set a fault after 1 trip with the malfunction present.
Refer to the Diagnostic Trouble Codes Description
Charts in this section and the appropriate Power-
train Diagnostic Procedure Manual for diagnostic
procedures.
NON-MONITORED CIRCUITS
The PCM does not monitor all circuits, systems
and conditions that could have malfunctions causing
driveability problems. However, problems with these
systems may cause the PCM to store diagnostic trou-
ble codes for other systems or components. For exam-
ple, a fuel pressure problem will not register a fault
directly, but could cause a rich/lean condition or mis-
fire. This could cause the PCM to store an oxygen
sensor or misfire diagnostic trouble code.
The major non-monitored circuits are listed below
along with examples of failures modes that do not
directly cause the PCM to set a DTC, but for a sys-
tem that is monitored.
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 diag-
nostic 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. It may set a EGR or Fuel
system fault or O2S.
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 mod-
ule 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 connec-
tor pins.
HIGH AND LOW LIMITS
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 diagnos-
tic 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.
NS
EMISSION CONTROL SYSTEMS
25 - 11
DESCRIPTION AND OPERATION (Continued)
Summary of Contents for 1998 Voyager
Page 8: ...FASTENER IDENTIFICATION NS INTRODUCTION 5 GENERAL INFORMATION Continued ...
Page 9: ...FASTENER STRENGTH 6 INTRODUCTION NS GENERAL INFORMATION Continued ...
Page 11: ...METRIC CONVERSION 8 INTRODUCTION NS GENERAL INFORMATION Continued ...
Page 12: ...TORQUE SPECIFICATIONS NS INTRODUCTION 9 GENERAL INFORMATION Continued ...
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Page 93: ...RED BRAKE WARNING LAMP FUNCTION NS BRAKES 5 11 DIAGNOSIS AND TESTING Continued ...
Page 94: ...POWER BRAKE SYSTEM DIAGNOSTICS 5 12 BRAKES NS DIAGNOSIS AND TESTING Continued ...
Page 95: ...VEHICLE ROAD TEST BRAKE NOISE NS BRAKES 5 13 DIAGNOSIS AND TESTING Continued ...
Page 222: ...COOLING SYSTEM DIAGNOSIS 7 8 COOLING SYSTEM NS DIAGNOSIS AND TESTING Continued ...
Page 223: ...NS COOLING SYSTEM 7 9 DIAGNOSIS AND TESTING Continued ...
Page 224: ...7 10 COOLING SYSTEM NS DIAGNOSIS AND TESTING Continued ...
Page 225: ...NS COOLING SYSTEM 7 11 DIAGNOSIS AND TESTING Continued ...
Page 226: ...7 12 COOLING SYSTEM NS DIAGNOSIS AND TESTING Continued ...
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Page 289: ...CHARGING SYSTEM SCHEMATIC TYPICAL NS CHARGING SYSTEM 8C 3 DIAGNOSIS AND TESTING Continued ...
Page 291: ...CHARGING SYSTEM TEST NS CHARGING SYSTEM 8C 5 DIAGNOSIS AND TESTING Continued ...
Page 292: ...OVERCHARGE TEST 8C 6 CHARGING SYSTEM NS DIAGNOSIS AND TESTING Continued ...
Page 294: ...VOLTAGE DROP TEST 8C 8 CHARGING SYSTEM NS ...
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Page 377: ...NS GS INSTRUMENT PANEL AND SYSTEMS 8E 5 DIAGNOSIS AND TESTING Continued ...
Page 378: ...8E 6 INSTRUMENT PANEL AND SYSTEMS NS GS DIAGNOSIS AND TESTING Continued ...
Page 379: ...NS GS INSTRUMENT PANEL AND SYSTEMS 8E 7 DIAGNOSIS AND TESTING Continued ...
Page 380: ...8E 8 INSTRUMENT PANEL AND SYSTEMS NS GS DIAGNOSIS AND TESTING Continued ...
Page 381: ...NS GS INSTRUMENT PANEL AND SYSTEMS 8E 9 DIAGNOSIS AND TESTING Continued ...
Page 382: ...8E 10 INSTRUMENT PANEL AND SYSTEMS NS GS DIAGNOSIS AND TESTING Continued ...
Page 383: ...NS GS INSTRUMENT PANEL AND SYSTEMS 8E 11 DIAGNOSIS AND TESTING Continued ...
Page 384: ...8E 12 INSTRUMENT PANEL AND SYSTEMS NS GS DIAGNOSIS AND TESTING Continued ...
Page 385: ...NS GS INSTRUMENT PANEL AND SYSTEMS 8E 13 DIAGNOSIS AND TESTING Continued ...
Page 386: ...8E 14 INSTRUMENT PANEL AND SYSTEMS NS GS DIAGNOSIS AND TESTING Continued ...
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Page 559: ...SPECIAL TOOLS SPECIAL TOOL Degausser 6029 NS OVERHEAD CONSOLE 8V 9 ...
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Page 564: ...8W 01 2 8W 01 GENERAL INFORMATION NS GS DESCRIPTION AND OPERATION Continued ...
Page 565: ...NS GS 8W 01 GENERAL INFORMATION 8W 01 3 DESCRIPTION AND OPERATION Continued ...
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Page 1220: ...Fig 3 Lubrication Lines 9 42 ENGINE NS GS DESCRIPTION AND OPERATION Continued ...
Page 1224: ...ENGINE DIAGNOSIS MECHANICAL CONT 9 46 ENGINE NS GS DIAGNOSIS AND TESTING Continued ...
Page 1286: ...Fig 5 Front Crossmember Dimensions 13 6 FRAME AND BUMPERS NS SPECIFICATIONS Continued ...
Page 1287: ...Fig 6 Engine Compartment Top View NS FRAME AND BUMPERS 13 7 SPECIFICATIONS Continued ...
Page 1289: ...Fig 8 Full Vehicle Bottom View NS FRAME AND BUMPERS 13 9 SPECIFICATIONS Continued ...
Page 1291: ...Fig 11 Body Side Openings NS FRAME AND BUMPERS 13 11 SPECIFICATIONS Continued ...
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Page 1302: ...FUEL PRESSURE BELOW SPECIFICATIONS 14 8 FUEL SYSTEM NS DIAGNOSIS AND TESTING Continued ...
Page 1304: ...FUEL INJECTOR DIAGNOSIS 14 10 FUEL SYSTEM NS DIAGNOSIS AND TESTING Continued ...
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Page 1479: ...Diagnosis Guide NS TRANSAXLE AND POWER TRANSFER UNIT 21 5 DIAGNOSIS AND TESTING Continued ...
Page 1480: ...Diagnosis Guide 21 6 TRANSAXLE AND POWER TRANSFER UNIT NS DIAGNOSIS AND TESTING Continued ...
Page 1481: ...Diagnosis Guide NS TRANSAXLE AND POWER TRANSFER UNIT 21 7 DIAGNOSIS AND TESTING Continued ...
Page 1482: ...Diagnosis Guide 21 8 TRANSAXLE AND POWER TRANSFER UNIT NS DIAGNOSIS AND TESTING Continued ...
Page 1483: ...Diagnosis Guide NS TRANSAXLE AND POWER TRANSFER UNIT 21 9 DIAGNOSIS AND TESTING Continued ...
Page 1484: ...Diagnosis Guide 21 10 TRANSAXLE AND POWER TRANSFER UNIT NS DIAGNOSIS AND TESTING Continued ...
Page 1485: ...Diagnosis Guide NS TRANSAXLE AND POWER TRANSFER UNIT 21 11 DIAGNOSIS AND TESTING Continued ...
Page 1486: ...Diagnosis Guide 21 12 TRANSAXLE AND POWER TRANSFER UNIT NS DIAGNOSIS AND TESTING Continued ...
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Page 1723: ...LEAD CORRECTION CHART NS TIRES AND WHEELS 22 5 DIAGNOSIS AND TESTING Continued ...
Page 1726: ...SPECIFICATIONS TIRE SPECIFICATIONS 22 8 TIRES AND WHEELS NS ...
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