shaft CHRYSLER VOYAGER 1996 Service Manual

(18) Remove weather-strip at fresh-air vent.
(19) Separate housing halves (Fig. 72).
(20) Pull up on separator plate and remove defrost
door (Fig. 73).
(21) Remove upper half Panel door (Fig. 74).(22) Remove upper half of Floor door (Fig. 75).
(23) Remove upper half of the blend-air door (slide
off of shaft) (Fig. 76).
Fig. 70 Front Cover
Fig. 71 View of Zone Control Doors
Fig. 72 Distribution Housing Halves
Fig. 73 Defrost Door
Fig. 74 Panel Door
Fig. 75 Floor Door
NS/GSHEATING AND AIR CONDITIONING 24 - 35
DISASSEMBLY AND ASSEMBLY (Continued)

DIAGNOSTIC TROUBLE CODE DESCRIPTIONS
HEX
CODEGENERIC
SCAN
TOOL
CODEDRB SCAN TOOL
DISPLAYDESCRIPTION OF DIAGNOSTIC
TROUBLE CODE
01 P0340 No Cam Signal at PCM No camshaft signal detected during engine
cranking.
02 P0601 Internal Controller Failure PCM Internal fault condition detected.
05 Charging System Voltage Too Low Battery voltage sense input below target charging
during engine operation. Also, no significant
change detected in battery voltage during active
test of generator output circuit.
06 Charging System Voltage Too High Battery voltage sense input above target charging
voltage during engine operation.
0A* Auto Shutdown Relay Control
CircuitAn open or shorted condition detected in the auto
shutdown relay circuit.
0B Generator Field Not Switching
ProperlyAn open or shorted condition detected in the
generator field control circuit.
0C P0743 Torque Converter Clutch Soleniod/
Trans Relay CircuitsAn open or shorted condition detected in the
torque converter part throttle unlock solenoid
control circuit (3 speed auto RH trans. only).
0E P1491 Rad Fan Control Relay Circuit An open or shorted condition detected in the low
speed radiator fan relay control circuit.
0F* Speed Control Solenoid Circuits An open or shorted condition detected in the
Speed Control vacuum or vent solenoid circuits.
10* A/C Clutch Relay Circuit An open or shorted condition detected in the A/C
clutch relay circuit.
11 P0403 EGR Solenoid Circuit An open or shorted condition detected in the EGR
transducer solenoid circuit.
12 P0443 EVAP Purge Solenoid Circuit An open or shorted condition detected in the duty
cycle purge solenoid circuit.
13 P0203 Injector #3 Control Circuit Injector #3 output driver does not respond properly
to the control signal.
14 P0202 Injector #2 Control Circuit Injector #2 output driver does not respond properly
to the control signal.
15 P0201 Injector #1 Control Circuit Injector #1 output driver does not respond properly
to the control signal.
19 P0505 Idle Air Control Motor Circuits A shorted or open condition detected in one or
more of the idle air control motor circuits.
1A P0122 Throttle Position Sensor Voltage
LowThrottle position sensor input below the minimum
acceptable voltage
1B P0123 Throttle Position Sensor Voltage
HighThrottle position sensor input above the maximum
acceptable voltage.
1E P0117 ECT Sensor Voltage Too Low Engine coolant temperature sensor input below
minimum acceptable voltage.
1F P0118 ECT Sensor Voltage Too High Engine coolant temperature sensor input above
maximum acceptable voltage.
25 - 4 EMISSION CONTROL SYSTEMSNS
DESCRIPTION AND OPERATION (Continued)

HEX
CODEGENERIC
SCAN
TOOL
CODEDRB SCAN TOOL
DISPLAYDESCRIPTION OF DIAGNOSTIC
TROUBLE CODE
92 P1496 5 Volt Supply Output Too Low 5 volt output from regulator does not meet
minimum requirement.
94* P0740 Torq Conv Clu, No RPM Drop At
LockupRelationship between engine speed and vehicle
speed indicates no torque converter clutch
engagement (auto. trans. only).
95* Fuel Level Sending Unit Volts Too
LowOpen circuit between PCM and fuel gauge sending
unit.
96* Fuel Level Sending Unit Volts Too
HighCircuit shorted to voltage between PCM and fuel
gauge sending unit.
97* Fuel Level Unit No Change Over
MilesNo movement of fuel level sender detected.
98 P0703 Brake Switch Stuck Pressed or
ReleasedNo release of brake switch seen after too many
accelerations.
99 P1493 Ambient/Batt Temp Sen VoltsToo
LowBattery temperature sensor input voltage below an
acceptable range.
9A P1492 Ambient/Batt Temp Sensor VoltsToo
HighBattery temperature sensor input voltage above an
acceptable range.
9B P0131 Right Rear (or just) Upstream O2S
Shorted to GroundO2 sensor voltage too low, tested after cold start.
9C P0137 Right Rear (or just) Downstream
O2S Shorted to GroundO2 sensor voltage too low, tested after cold start.
9D P1391 Intermittent Loss of CMP or CKP Intermittent loss of either camshaft or crankshaft
position sensor
A0 P0442 Evap Leak Monitor Small Leak
DetectedA small leak has been detected by the leak
detection monitor.
A1 P0455 Evap Leak Monitor Large Leak
DetectedThe leak detection monitor is unable to pressurize
Evap system, indicating a large leak.
AE P0305 Cylinder #5 Mis-fire Misfire detected in cylinder #5.
AF P0306 Cylinder #6 Mis-fire Misfire detected in cylinder #6.
B7 P1495 Leak Detect ion Pump Solenoid
CircuitLeak detection pump solenoid circuit fault (open or
short).
B8 P1494 Leak Detect Pump Sw or
Mechanical FaultLeak detection pump switch does not respond to
input.
BA P1398 Mis-fire Adaptive Numerator at Limit CKP sensor target windows have too much
variation
BB P1486 Evap Leak Monitor Pinched Hose
FoundPlug or pinch detected between purge solenoid
and fuel tank.
BE P1290 CNG System Pressure Too High Compressed natural gas pressure sensor reading
above acceptable voltage.
C0 P0133 Cat Mon Slow O2 Upstream Oxygen sensor response slower than minimum
required switching frequency during catalyst
monitor.
* Check Engine Lamp (MIL) will not illuminate if this Diagnostic Trouble Code was recorded.
NSEMISSION CONTROL SYSTEMS 25 - 7
DESCRIPTION AND OPERATION (Continued)

conditions are met, the EGR is turned off (solenoid
energized) and the O2S compensation control is mon-
itored. Turning off the EGR shifts the air fuel (A/F)
ratio in the lean direction. The O2S data should indi-
cate an increase in the O2 concentration in the com-
bustion chamber when the exhaust gases are no
longer recirculated. While this test does not directly
measure the operation of the EGR system, it can be
inferred from the shift in the O2S data whether the
EGR system is operating correctly. Because the O2S
is being used, the O2S test must pass its test before
the EGR test.
HEX 6A,6B, 6C, 6D, 6E, AE, and AFÐMISFIRE
MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
HEX 76, 77, 78, and 79ÐFUEL SYSTEM
MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the air fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S output. The programmed memory
acts as a self calibration tool that the engine control-
ler uses to compensate for variations in engine spec-
ifications, sensor tolerances and engine fatigue over
the life span of the engine. By monitoring the actual
air-fuel ratio with the O2S (short term) and multiply-
ing that with the program long-term (adaptive) mem-
ory and comparing that to the limit, it can be
determined whether it will pass an emissions test. If
a malfunction occurs such that the PCM cannot
maintain the optimum A/F ratio, then the MIL will
be illuminated.
HEX 70, and B4ÐCATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.Normal vehicle miles or engine misfire can cause a
catalyst to decay. A meltdown of the ceramic core can
cause a reduction of the exhaust passage. This can
increase vehicle emissions and deteriorate engine
performance, driveability and fuel economy.
The catalyst monitor uses dual oxygen sensors
(O2S's) to monitor the efficiency of the converter. The
dual O2Ss strategy is based on the fact that as a cat-
alyst deteriorates, its oxygen storage capacity and its
efficiency are both reduced. By monitoring the oxy-
gen storage capacity of a catalyst, its efficiency can
be indirectly calculated. The upstream O2S is used to
detect the amount of oxygen in the exhaust gas
before the gas enters the catalytic converter. The
PCM calculates the A/F mixture from the output of
the O2S. A low voltage indicates high oxygen content
(lean mixture). A high voltage indicates a low content
of oxygen (rich mixture).
When the upstream O2S detects a lean condition,
there is an abundance of oxygen in the exhaust gas.
A functioning converter would store this oxygen so it
can use it for the oxidation of HC and CO. As the
converter absorbs the oxygen, there will be a lack of
oxygen downstream of the converter. The output of
the downstraem O2S will indicate limited activity in
this condition.
As the converter loses the ability to store oxygen,
the condition can be detected from the behavior of
the downstream O2S. When the efficiency drops, no
chemical reaction takes place. This means the con-
centration of oxygen will be the same downstream as
upstream. The output voltage of the downstream
O2S copies the voltage of the upstream sensor. The
only difference is a time lag (seen by the PCM)
between the switching of the O2S's.
To monitor the system, the number of lean-to-rich
switches of upstream and downstream O2S's is
counted. The ratio of downstream switches to
upstream switches is used to determine whether the
catalyst is operating properly. An effective catalyst
will have fewer downstream switches than it has
upstream switches i.e., a ratio closer to zero. For a
totally ineffective catalyst, this ratio will be one-to-
one, indicating that no oxidation occurs in the device.
The system must be monitored so that when cata-
lyst efficiency deteriorates and exhaust emissions
increase to over the legal limit, the MIL (check
engine lamp) will be illuminated.
HEX A0, A1, B7, and B8ÐLEAK DETECTION
PUMP MONITOR
The leak detection assembly incorporates two pri-
mary functions: it must detect a leak in the evapora-
tive system and seal the evaporative system so the
leak detection test can be run.
NSEMISSION CONTROL SYSTEMS 25 - 9
DESCRIPTION AND OPERATION (Continued)

²An EGR Solenoid. The EGR solenoid is located
in the engine compartment next to the PDC (Fig. 3).
The EGR solenoid opens and closes the vaccum sup-
ply that opens and closes the EGR valve. The
amount of time the EGR solenoid is held open is con-
trolled by the PCM. This is referred to as the ªon
timeº of the EGR valve.
²An EGR tube (Fig. 2) connecting a passage in
the EGR valve to the rear of the exhaust manifold.
²The vacuum pump, which supplies vacuum for
the EGR Solenoid valve. This pump also supplies
vacuum for operation of the power brake booster. The
pump is located internally in the front of the engine
block (Fig. 4) and is driven by the crankshaft gear.
²Vacuum lines and hoses to connect the various
components.
When the PCM supplies a ªonº or ªoffº signal to the
EGR Solenoid by grounding the circuit, EGR system
operation starts to occur. The PCM will monitor var-
ious engine conditions and determine when to supply
and remove this ground signal. Some of the engine
conditions that are monitored are the engine coolant
temperature, throttle position and engine speed sen-
sors.
When the ground signal is supplied to the EGR
Solenoid, vacuum from the vacuum pump will be
allowed to pass to the EGR valve via a connecting
hose.
Exhaust gas recirculation will begin in this order
when:
²The PCM determines that EGR system opera-
tion is necessary.²The engine is running to operate the vacuum
pump.
²A ground signal is supplied to the EVM.
²Vacuum passes to the EGR valve.
²The 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 PCM
after 60 seconds of continuous engine idling to
improve idle quality.
DIAGNOSIS AND TESTING
EGR GAS FLOW TEST
Use the following test procedure to determine if
exhaust gas is flowing through the EGR valve. It can
also be used to determine if the EGR tube is plugged,
or the system passages in the intake or exhaust man-
ifolds are plugged.
This is not to be used as a complete test of the
EGR system.
The engine must be started, running and warmed
to operating temperature for this test.
(1) All EGR valves are equipped with a vacuum
supply fitting located on the EGR valve vacuum
motor (Fig. 2).
(2) Disconnect the rubber hose from the vacuum
supply fitting (Fig. 2).
(3) Connect a hand±held vacuum pump to this fit-
ting.
(4) Start the engine.
Fig. 3 EGR Solenoid
Fig. 4 Internal Vacuum Pump
25 - 6 EMISSION CONTROL SYSTEMNS/GS
DESCRIPTION AND OPERATION (Continued)