2001 DODGE TOWN AND COUNTRY sensor

EMISSIONS CONTROL 2.5L TURBO DIESEL
TABLE OF CONTENTS
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EMISSIONS CONTROL 2.5L TURBO DIESEL
DESCRIPTION............................1
SPECIFICATIONS.........................2EXHAUST GAS RECIRCULATION.............3
ON-BOARD DIAGNOSTICS..................6
EMISSIONS CONTROL 2.5L
TURBO DIESEL
DESCRIPTION
The 2.5L diesel Engine Control Module (ECM) con-
trols many different circuits in the fuel injection
pump and engine systems. If the ECM senses a prob-
lem with a monitored circuit that indicates an actual
problem, a Diagnostic Trouble Code (DTC) will be
stored in the ECM's memory, and eventually may
illuminate the MIL (Malfunction Indicator Lamp)
constantly while the key is on. If the problem is
repaired, or is intermittent, the ECM will erase the
DTC after 40 warm-up cycles without the the fault
detected. A warm-up cycle consists of starting the
vehicle when the engine is cold, then the engine is
warmed up to a certain temperature, and finally, the
engine temperature falls to a normal operating tem-
perature, then the key is turned off.
Certain criteria must be met for a DTC to be
entered into ECM memory. The criteria may be a
specific range of engine rpm, engine or fuel tempera-
ture and/or input voltage to the ECM. A DTC indi-
cates that the ECM has identified an abnormal
signal in a circuit or the system.
There are several operating conditions that the
ECM does not monitor and set a DTC for. Refer to
the following Monitored Circuits and Non±Monitored
Circuits in this section.
ECM MONITORED SYSTEMS
The ECM can detect certain problems in the elec-
trical system.
Open or Shorted Circuit± The ECM will not
distinguish between an open or a short to ground,
however the ECM can determine if there is excessive
current on a circuit, such as a short to voltage or a
decrease in component resistance.
Output Device Current Flow± The ECM senses
whether the output devices are electrically connected.
If there is a problem with the circuit, the ECM
senses whether the circuit is open, shorted to ground
(±), or shorted to (+) voltage.Fuel Pressure:Fuel pressure is controlled by the
fuel injection pump and fuel pressure solenoid. The
ECM uses a fuel pressure sensor to determine if a
fuel pressure problem exists.
Fuel Injector Malfunctions:The ECM can deter-
mine if a fuel injector has an electrical problem. The
fuel injectors on the diesel engine arecontrolledby
the ECM.
ECM NON±MONITORED SYSTEMS
The ECM 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.
Cylinder Compression:The ECM cannot detect
uneven, low, or high engine cylinder compression.
Exhaust System:The ECM cannot detect a
plugged, restricted or leaking exhaust system.
Vacuum Assist:Leaks or restrictions in the vac-
uum circuits of the Exhaust Gas Recirculation Sys-
tem (EGR) are not monitored by the ECM.
ECM System Ground:The ECM cannot deter-
mine a poor system ground. However, a DTC may be
generated as a result of this condition.
ECM/PCM Connector Engagement:The ECM
cannot determine spread or damaged connector pins.
However, a DTC may be generated as a result of this
condition.
HIGH AND LOW LIMITS
The ECM compares input signals from each input
device. It has high and low limits that are pro-
grammed into it for that device. If the inputs are not
within specifications and other DTC criteria are met,
a DTC will be stored in memory. Other DTC criteria
might include engine rpm limits or input voltages
from other sensors or switches. The other inputs
might have to be sensed by the ECM when it senses
a high or low input voltage from the control system
device in question.
RGEMISSIONS CONTROL 2.5L TURBO DIESEL25a-1
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EXHAUST GAS RECIRCULATION
TABLE OF CONTENTS
page page
EXHAUST GAS RECIRCULATION
DESCRIPTION............................3
OPERATION.............................3
VA LV E
DESCRIPTION............................3
OPERATION.............................4REMOVAL...............................4
INSTALLATION............................4
VALVE COOLER
DESCRIPTION............................4
REMOVAL...............................4
INSTALLATION............................5
EXHAUST GAS
RECIRCULATION
DESCRIPTION
The EGR system reduces oxides of nitrogen (NOx)
in the engine exhaust. This is accomplished by allow-
ing a predetermined amount of hot exhaust gas to
recirculate and dilute the incoming fuel/air mixture.
A malfunctioning EGR system can cause engine
stumble, sags, or hesitation, rough idle, engine stall-
ing and poor driveability.
OPERATION
The system consists of:
²An EGR valve assembly. The valve is located on
the rear of the engine above the exhaust manfiold.
²An EGR solenoid.The EGR solenoid controls the
ªon timeº of the EGR valve.
²The ECM operates the EGR solenoid. The ECM
is located inside the vehicle under the instrument
panel.
²An EGR tube connects a passage in the EGR
valve to the rear of the exhaust manifold.
²The vacuum pump supplies vacuum for the EGR
solenoid and the EGR valve. This pump also supplies
vacuum for operation of the power brake boosterb
and the heating and air conditioning system. The
pump is located internally in the front of the engine
block and is driven by the crankshaft gear.
²Vacuum lines and hoses connect the various
components.
When the ECM supplies a variable ground signal
to the EGR solenoid, EGR system operation starts to
occur. The ECM will monitor and determine when tosupply and remove this variable ground signal. This
will depend on inputs from the engine coolant tem-
perature, throttle position and engine speed sensors.
When the variable ground signal is supplied to the
EGR solenoid, vacuum from the vacuum pump will
be allowed to pass through the EGR solenoid and on
to the EGR valve with a connecting hose.
Exhaust gas recirculation will begin in this order
when:
²The ECM determines that EGR system opera-
tion is necessary.
²The engine is running to operate the vacuum
pump.
²A variable ground signal is supplied to the EGR
solenoid.
²Variable vacuum passes through the EGR sole-
noid 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 ECM
after 60 seconds of continuous engine idling to
improve idle quality.
VA LV E
DESCRIPTION
The EGR system consists of (Fig. 1):
²EGR valve
²EGR tube
²Vacuum hoses
²EGR cooler
²EGR solenoid
RGEXHAUST GAS RECIRCULATION25a-3
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ON-BOARD DIAGNOSTICS
TABLE OF CONTENTS
page
ON-BOARD DIAGNOSTICS
DESCRIPTION............................6
ON-BOARD DIAGNOSTICS
DESCRIPTION - DIAGNOSTIC TROUBLE CODES
On the following pages, a list of DTC's is provided
for the 2.5L diesel engine. A DTC indicates that the
ECM has recognized an abnormal signal in a circuit
or the system. A DTC may indicate the result of a
failure, but most likely will not identify the failed
component directly. Refer to the appropriate diagnos-
tic manual for more information on diagnosis of trou-
ble codes.
ACCESSING DIAGNOSTIC TROUBLE CODES
A stored DTC can be displayed through the use of
the DRB IIItscan tool. The DRB IIItconnects to the
data link connector. The data link connector is
located under the instrument panel near bottom of
the steering column (Fig. 1).
ERASING TROUBLE CODES
After the problem has been repaired, use the DRB
IIItscan tool to erase a DTC.
ENGINE CONTROL MODULE (ECM) - DRBIIITCODES
Generic Scan Tool Code DRB IIITScan Tool Display
P0070 Ambient Air Temperature Circuit Signal Voltage Too High
Ambient Air Temperature Circuit Signal Voltage Too Low
P0100 Mass Air Flow Sensor Plausibility
Mass Air Flow Sensor Plausibility Positive Area
Mass Air Flow Sensor Signal Voltage Too High
Mass Air Flow Sensor Signal Voltage Too Low
Mass Air Flow Sensor Supply Voltage Too High Or Low
P0105 Barometric Pressure Circuit Signal Voltage To High
Barometric Pressure Circuit Signal Voltage To Low
P0110 Intake Air Temperature Sensor Circuit Signal Too High
Intake Air Temperature Sensor Circuit Signal Too Low
Fig. 1 DATA LINK CONNECTOR
25a - 6 ON-BOARD DIAGNOSTICSRG
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Generic Scan Tool Code DRB IIITScan Tool Display
P0115 Engine Coolant Temperature Sensor Circuit Engine Is Cold Too Long
Engine Coolant Temperature Sensor Circuit Voltage To Low
Engine Coolant Temperature Sensor Circuit Voltage To High
P0190 Fuel Pressure Sensor Circuit MALF Signal Voltage Too High
Fuel Pressure Sensor Circuit MALF Signal Voltage Too Low
P0195 Oil Temperature Sensor Circuit MALF Signal Voltage Too High
Oil Temperature Sensor Circuit MALF Signal Voltage Too Low
P0201 Cylinder 1 Injector Circuit Current Decrease
Cylinder 1 Injector Circuit Load Drop
Cylinder 1 Injector Circuit Overcurrent High Side
Cylinder 1 Injector Circuit Overcurrent Low Side
P0202 Cylinder 2 Injector Circuit Current Decrease
Cylinder 2 Injector Circuit Load Drop
Cylinder 2 Injector Circuit Overcurrent High Side
Cylinder 2 Injector Circuit Overcurrent Low Side
P0203 Cylinder 3 Injector Circuit Current Decrease
Cylinder 3 Injector Circuit Load Drop
Cylinder 3 Injector Circuit Overcurrent High Side
Cylinder 3 Injector Circuit Overcurrent Low Side
P0204 Cylinder 4 Injector Circuit Current Decrease
Cylinder 4 Injector Circuit Load Drop
Cylinder 4 Injector Circuit Overcurrent High Side
Cylinder 4 Injector Circuit Overcurrent Low Side
P0235 Boost Pressure Sensor Plausibility
Boost Pressure Sensor Signal Voltage Too Low
Boost Pressure Sensor Signal Voltage Too High
Boost Pressure Sensor Signal Voltage Too High Or Low
P0335 CKP Position Sensor Circuit Dynamic Plausibility
CKP Position Sensor Circuit Overspeed Recognition
CKP Position Sensor Circuit Static Plausibility
P0340 CMP Position Sensor Circuit CMP/CKP Sync. Failure
CMP Position Sensor Circuit Dynamic Plausibility
CMP Position Sensor Circuit Fuel Shut-Off Activated
CMP Position Sensor Circuit Signal Frequency Too High
CMP Position Sensor Circuit Static Plausibility
P0380 Glow Plug Circuit A Open Circuit
Glow Plug Circuit A Short Circuit
RGON-BOARD DIAGNOSTICS25a-7
ON-BOARD DIAGNOSTICS (Continued)
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Generic Scan Tool Code DRB IIITScan Tool Display
P0403 EGR Solenoid Circuit Open Circuit
EGR Solenoid Circuit Short Circuit
P0480 Fan 1 Control Circuit Open Circuit
Fan 1 Control Circuit Short Circuit
P0481 Fan 2 Control Circuit Open Circuit
Fan 2 Control Circuit Short Circuit
P0500 Vehicle Speed Sensor Frequency Too High
Vehicle Speed Sensor Frequency High Level Duration
Vehicle Speed Sensor Plausibility
Vehicle Speed Sensor Signal Voltage Too High
P0514 Battery Temperature Sensor Circuit Signal Voltage Too High
P0520 Oil Pressure Sensor Circuit MALF Signal Voltage Too High
Oil Pressure Sensor Circuit MALF Signal Voltage Too Low
Oil Pressure Sensor Circuit MALF Signal Voltage Too Low or High
P0530 A/C Pressure Sensor Circuit Plausibility
A/C Pressure Sensor Circuit Signal Voltage Too High
A/C Pressure Sensor Circuit Signal Voltage Too Low
A/C Pressure Sensor Circuit Supply Voltage Too High Or Low
P0560 System Voltage Too High
System Voltage Too Low
P0579 Speed Control Switch Signal Circuit Voltage Too High
Speed Control Switch Signal Circuit Voltage Too Low
P0606 ECM Error Gate Array - Communication
ECM Error Gate Array - Communication Not Verified
ECM Error Gate Array - Quantity Stop
ECM Error Gate Array - Has Occurred
ECM Error Redundant Overrun Monitoring
P0615 Starter Relay Circuit Open Circuit
Starter Relay Circuit Short Circuit
P0620 Generator Field Control MALF Open Circuit
Generator Field Control MALF Short Circuit
P0641 Sensor Reference Voltage A CKT Voltage Too High
Sensor Reference Voltage A CKT Voltage Too Low
P0645 A/C Clutch Relay Circuit Open Circuit
A/C Clutch Relay Circuit Short Circuit
P0651 Sensor Reference Voltage B CKT Voltage Too Low
Sensor Reference Voltage B CKT Voltage Too High
25a - 8 ON-BOARD DIAGNOSTICSRG
ON-BOARD DIAGNOSTICS (Continued)
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Generic Scan Tool Code DRB IIITScan Tool Display
P1703 Brake Switch Signal CKTS Plaus. With Redundant Contact After
Initialization
P2120 Acc. Pedal Position Sensor 1 CKT Plausibility
Acc. Pedal Position Sensor 1 CKT Plausibility With Brake Switch
Acc. Pedal Position Sensor 1 CKT Plausibility With Potentiometer
Acc. Pedal Position Sensor 1 CKT Signal Voltage Too High
Acc. Pedal Position Sensor 1 CKT Signal Voltage Too Low
Acc. Pedal Position Sensor 1 CKT Signal Voltage Too High or Low
25a - 10 ON-BOARD DIAGNOSTICSRG
ON-BOARD DIAGNOSTICS (Continued)
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