oil reset CHRYSLER VOYAGER 2000 Diagnostic Manual

3.2.3 OTHER CONTROLS
CHARGING SYSTEM
The charging system is turned on when the
engine is started and ASD relay energized. When
the ASD relay is on, ASD output voltage is supplied
to the ASD sense circuit at the PCM. This voltage is
connected in some cases, through the PCM and
supplied to one of the generator field terminals
(Gen Source +). All others, the Gen field is con-
nected directly to the ASD output voltage. The
amount of current produced by the generator is
controlled by the Electronic Voltage Regulator
(EVR) circuitry, in the PCM. A battery temperature
sensor, located either in the battery tray, using the
ambient sensor, or in the PCM itself, is used to
sense battery temperature. This temperature along
with sensed line voltage, is used by the PCM to vary
the battery charging rate. This is done by cycling
the ground path to the other generator field termi-
nal (Gen field driver).
SPEED CONTROL SYSTEM
The PCM controls vehicle speed by operation of
the speed control servo vacuum and vent solenoids.
Energizing the vacuum solenoid applies vacuum to
the servo to increase throttle position. Operation of
the vent solenoid slowly releases the vacuum allow-
ing throttle position to decrease. A special dump
solenoid allows immediate release of throttle posi-
tion caused by braking, cruise control switch turned
off, shifting into neutral, excessive RPM (tires spin-
ning) or ignition key off.
3.2.4 PCM OPERATING MODES
As input signals to the powertrain control module
(PCM) change, the PCM adjusts its response to
output devices. For example, the PCM must calcu-
late a different injector pulse width and ignition
timing for idle than it does for wide open throttle.
There are several different modes of operation that
determine how the PCM responds to the various
input signals.
There are two types of engine control operation:
open loopandclosed loop.
In open loop operation, the PCM receives input
signals and responds according to preset program-
ming. Inputs from the heated oxygen sensors are
not monitored.
In closed loop operation, the PCM monitors the
inputs from the heated oxygen sensors. This input
indicates to the PCM whether or not the calculated
injector pulse width results in the ideal air-fuel
ratio of 14.7 parts air to 1 part fuel. By monitoring
the exhaust oxygen content through the oxygen
sensor, the PCM can fine tune injector pulse width.
Fine tuning injector pulse width allows the PCM toachieve the lowest emission levels while maintain-
ing optimum fuel economy.
The engine start-up (crank), engine warm-up,
and wide open throttle modes are open loop modes.
Under most operating conditions, closed loop modes
occur with the engine at operating temperature.
IGNITION SWITCH ON (ENGINE OFF) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
1. The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic
fuel strategy.
2. The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input.
The PCM modifies fuel strategy based on this
input.
When the key is in the ªonº position and the
engine is not running (zero rpm), the auto shut-
down relay and fuel pump relay are not energized.
Therefore, voltage is not supplied to the fuel pump,
ignition coil, and fuel injectors.
Engine Start-up Mode -This is an open loop
mode. The following actions occur when the starter
motor is engaged:
1. The auto shutdown and fuel pump relays are
energized. If the PCM does not receive the cam-
shaft and crankshaft signal within approxi-
mately one second, these relays are de-
energized.
2. The PCM energizes all fuel injectors until it
determines crankshaft position from the cam-
shaft and crankshaft signals. The PCM deter-
mines crankshaft position within one engine
revolution. After the crankshaft position has
been determined, the PCM energizes the fuel
injectors in sequence. The PCM adjusts the in-
jector pulse width and synchronizes the fuel
injectors by controlling the fuel injectors' ground
paths.
3. Once the engine idles within 64 rpm of its target
engine speed, the PCM compares the current
MAP sensor value with the value received dur-
ing the ignition switch on (zero rpm) mode. A
diagnostic trouble code is written to PCM mem-
ory if a minimum difference between the two
values is not found.
Once the auto shutdown and fuel pump relays
have been energized, the PCM determines the fuel
injector pulse width based on the following:
± engine coolant temperature
± manifold absolute pressure
± intake air temperature
± engine revolutions
± throttle position
4
GENERAL INFORMATION
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Verification Tests
VERIFICATION TEST VER-1A APPLICABILITY
No Start Verification
Use this test to verify that a No Start condition has been repaired and that the vehicle can be
returned to the customer.
Note: If the Powertrain Control Module has been replaced and the correct VIN and
mileage have not been programmed, a DTC will be set in the ABS, Airbag and the
SKIM modules. In addition, if the vehicle is equipped with a Sentry Key Immobilizer
Module (SKIM), Secret Key data must be updated to enable starting. Refer to
GENERAL INFORMATION section for programming information for the PCM, SKIM
and the Transponder (ignition key).
1. Inspect the vehicle to ensure that all components related to the repair are connected
properly.
2. Inspect the engine oil for fuel contamination. Replace the oil and filter as necessary
3. Attempt to start the engine.
4. If the No Start condition is still present, refer to the symptom list and perform diagnostic
testing as necessary. Refer to any Technical Service Bulletins that may apply.
5. Run the engine for one warm-up cycle to verify proper operation. With the DRBIIIt, confirm
that no DTC's are present and that all components are functioning properly.
6. If DTC's are present, refer to the symptom list and perform diagnostic testing as necessary.ALL
VERIFICATION TEST VER-2A APPLICABILITY
Non-OBDII Verification
Use this test to verify that a non-OBDII symptom has been repaired and that the vehicle can
be returned to the customer. A non-OBDII symptom is a comprehensive component related
symptom that is not the result of a failed OBDII major monitor.
Note: If the Powertrain Control Module has been replaced and the correct VIN and
mileage have not been programmed, a DTC will be set in the ABS, Airbag and the
SKIM modules. In addition, if the vehicle is equipped with a Sentry Key Immobilizer
Module (SKIM), Secret Key data must be updated to enable starting. Refer to
GENERAL INFORMATION section for programming information for the PCM, SKIM
and the Transponder (ignition key).
1. Inspect the vehicle to ensure that all components related to the repair are connected
properly.
2. With the DRBIIIt, Clear DTC's and Reset Memory (all engine values).
3. Run the engine for one warm-up cycle to verify proper operation.
4. Road test the vehicle. Use all accessories that may be related to this repair.
With the DRBIIIt, confirm that no DTC's are present and that all components are functioning
properly.
6. If this test is being performed after a No Trouble Code test, verify that the symptom is no
longer present. If the symptom is still present, or any other symptom or DTC is present, refer
to the symptom list for further diagnostic testing procedures. Check for any Technical Service
Bulletins that may apply.
7. If there are no DTC's present and all components are functioning properly, repair is
complete.ALL
317
VERIFICATION TESTS
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