injection pump CHRYSLER VOYAGER 1996 Workshop Manual

the current draw will drop to approximately 9±12
amps per plug.
Total momentary current draw for all four plugs is
approximately 100 amps on a cold engine dropping to
a total of approximately 40 amps after the plugs are
heated.
Electrical operation of the glow plugs are con-
trolled by the glow plug relay. Refer to the previous
Glow Plug RelayÐPCM Output for additional infor-
mation.
EXHAUST GAS RECIRCULATION (EGR)
SOLENOIDÐPCM OUTPUT
This circuit controls operation of the Exhaust Gas
Recirculation (EGR) solenoid. The EGR solenoid (Fig.
11) controls operation of the EGR valve.
Refer to Group 25, Emission Control System for
information. See EGR solenoid.
DIAGNOSIS AND TESTING
DIESEL DIAGONSTICS
The PCM controller does engine off diagonstics
tests, which may be heard for about 60 seconds after
turning the key off.
DIESEL PCM RELAY TEST
To perform a test of the relay and its related cir-
cuitry, refer to the DRB scan tool. To test the relay
only, refer to RelaysÐOperation/Testing in this sec-
tion of the group.
Diagnostic Trouble Codes:Refer to On-Board
Diagnostics in Group 25, Emission Control System
for a list of Diagnostic Trouble Codes (DTC's) for cer-
tain fuel system components.
ENGINE SPEED SENSOR TEST
To perform a test of the engine speed sensor and
its related circuitry, refer to the DRB scan tool.
Diagnostic Trouble Codes:Refer to On-Board
Diagnostics in Group 25, Emission Control System
for a list of Diagnostic Trouble Codes (DTC's) for cer-
tain fuel system components.
ENGINE COOLANT TEMPERATURE SENSOR TEST
The sensor is located on the side of cylinder head
near the rear of fuel injection pump (Fig. 13).
For a list of Diagnostic Trouble Codes (DTC's) for
certain fuel system components, refer to On-Board
Diagnostics in Group 25, Emission Control System.
To test the sensor only, refer to the following:
(1) Disconnect wire harness connector from coolant
temperature sensor.
(2) Test the resistance of the sensor with a high
input impedance (digital) volt±ohmmeter. The resis-
tance (as measured across the sensor terminals)should be less than 1340 ohms with the engine
warm. Refer to the following Sensor Resistance
(OHMS) chart. Replace the sensor if it is not within
the range of resistance specified in the chart.
(3) Test continuity of the wire harness. Do this
between the PCM wire harness connector and the
sensor connector terminal. Also test continuity of
wire harness to the sensor connector terminal. Refer
Fig. 13 Engine Coolant Temperature Sensor
Location
SENSOR RESISTANCE (OHMS)
14 - 50 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)

(2) Remove the sensor mounting bolts.
(3) Remove the sensor.
INSTALLATION
(1) Install the sensor flush against the opening in
the transmission housing.
(2) Install and tighten the sensor mounting bolt to
19 N´m (14 ft. lbs.) torque.
(3) Connect the electrical connector to the sensor.
ENGINE COOLANT TEMPERATURE SENSOR
The sensor is located on the side of cylinder head
near the rear of fuel injection pump (Fig. 19).
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
REFER TO GROUP 7, COOLING.
(1) Partially drain cooling system. Refer to Group
7, Cooling.
(2) Disconnect electrical connector from sensor.
(3) Remove sensor from cylinder head.
INSTALLATION
(1) Install a new copper gasket to sensor.
(2) Install sensor to cylinder head.
(3) Tighten sensor to 18 N´m (13 ft. lbs.) torque.
(4) Connect electrical connector to sensor.
(5) Replace any lost engine coolant. Refer to Group
7, Cooling System.
GLOW PLUGS
The glow plugs are located above each fuel injector
(Fig. 20). Four individual plugs are used.
REMOVAL
(1) Disconnect the negative battery cable at the
battery.
(2) Clean the area around the glow plug with com-
pressed air before removal.
(3) Disconnect electrical connector (Fig. 21) at glow
plug.
(4) Remove the glow plug (Fig. 20) from cylinder
head.
Fig. 18 Engine Speed SensorFig. 19 Engine Coolant Temperature Sensor
Location
Fig. 20 Glow Plug
14 - 54 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
REMOVAL AND INSTALLATION (Continued)

EMISSION CONTROL SYSTEM
CONTENTS
page page
EMISSION CONTROL SYSTEMÐ
2.0L ENGINE.......................... 9
EXHAUST EMISSION CONTROLSÐ
2.5L DIESEL ENGINE................... 5ON-BOARD DIAGNOSTICSÐ
2.5L DIESEL ENGINE................... 1
ON-BOARD DIAGNOSTICSÐ2.5L DIESEL ENGINE
INDEX
page page
GENERAL INFORMATION
SYSTEM DESCRIPTIONÐ
2.5L DIESEL ENGINE................... 1DESCRIPTION AND OPERATION
DIAGNOSTIC TROUBLE CODES............ 2
GENERAL INFORMATION
SYSTEM DESCRIPTIONÐ2.5L DIESEL ENGINE
The 2.5L diesel Powertrain Control Module (PCM)
monitors and controls many different circuits in the
fuel injection pump and engine systems. If the PCM
senses a problem with a monitored circuit that indi-
cates an actual problem, a Diagnostic Trouble Code
(DTC) will be stored in the PCM's memory, and even-
tually will illuminate the Diesel Glow Plug lamp con-
stantly while the key is on. If the problem is
repaired, or is intermittent, the PCM will erase the
DTC after 40 warm-up cycles. A warm-up cycle con-
sists of starting the vehicle when the engine is cold,
then the engine to warms up to a certain tempera-
ture, and finally, the engine temperature falls to a
normal operating temperature, then the key is
turned off.
Certain criteria must be met for a DTC to be
entered into PCM memory. The criteria may be a
specific range of engine rpm, engine or fuel tempera-
ture and/or input voltage to the PCM. A DTC indi-
cates that the PCM has identified an abnormal
signal in a circuit or the system. A DTC may indicate
the result of a failure, but never identify the failed
component directly.
There are several operating conditions that the
PCM does not monitor and set a DTC for. Refer to
the following Monitored Circuits and Non±Monitored
Circuits in this section.
MONITORED CIRCUITS
The PCM can detect certain problems in the elec-
trical system.
Open or Shorted Circuit± The PCM can deter-
mine if sensor output (which is the input to PCM) is
within proper range. It also determines if the circuit
is open or shorted.
Output Device Current Flow± The PCM senses
whether the output devices are electrically connected.
If there is a problem with the circuit, the PCM
senses whether the circuit is open, shorted to ground
(±), or shorted to (+) voltage.
NON±MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems or conditions that could have malfunctions
that result in driveability problems. A DTC will not
be displayed for these conditions.
Fuel Pressure:Fuel pressure is controlled by the
fuel injection pump. The PCM cannot detect prob-
lems in this component.
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.
Fuel Injector Malfunctions:The PCM cannot
determine if the fuel injector is clogged, or the wrong
injector is installed. The fuel injectors on the diesel
engine arenot controlledby the PCM, although a
NS/GSEMISSION CONTROL SYSTEM 25 - 1