2002 DODGE RAM PCM

(5) Place the HVAC housing right side up on the
work bench.
(6) Separate the top half of the HVAC housing
from the bottom half and set it aside.
ASSEMBLY
(1) Position the top half of the HVAC housing over
the bottom half. Be certain that the mode door pivot
pins are properly inserted in their pivot holes.
(2) Place the HVAC housing upside down on the
work bench.
(3) Install and tighten the screws on the bottom of
the HVAC housing that secure the two housing
halves together. Tighten the screws to 2.2 N´m (20 in.
lbs.).
(4) Snap the center heat duct adaptor onto the bot-
tom of the HVAC housing.
(5) Slide the floor duct onto the center heat duct
adaptor and secure it with a screw to the bottom of
the HVAC housing. Tighten the mounting screw to
2.2 N´m (20 in. lbs.).
INSTALLATION
(1) Position the HVAC housing to the dash panel.
Be certain that the evaporator condensate drain tube
and the housing mounting studs are inserted into
their correct mounting holes.
(2) Install the nuts that secure the HVAC housing
to the mounting studs on the passenger compartment
side of the dash panel. Tighten the nuts to 4.5 N´m
(40 in. lbs.).
(3) Install and tighten the nuts onto the HVAC
housing mounting studs on the engine compartment
side of the dash panel. Tighten the nuts to 7 N´m (60
in. lbs.).
(4) Unplug or remove the tape from the heater
core tubes. Connect the heater hoses to the heater
core tubes and fill the engine cooling system(Refer to
7 - COOLING - STANDARD PROCEDURE) and
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(5) If the vehicle is not equipped with air condi-
tioning, go to Step 10. If the vehicle is equipped with
air conditioning, install the accumulator. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
ACCUMULATOR - INSTALLATION) Connect the
accumulator inlet tube coupler to the evaporator out-
let tube. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
A/C LINE COUPLERS)
(6) Unplug or remove the tape from the liquid line
and the evaporator inlet tube fittings. Connect the
liquid line coupler to the evaporator inlet tube. (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - A/C LINE COU-
PLERS)(7) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(8) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
(9) Reinstall the PCM to the dash panel. Refer to
Electronic Control Modules for the procedures.
(10) Reinstall the instrument panel in the vehi-
cle(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY -
INSTALLATION).
(11) Connect the battery negative cable.
(12) Start the engine and check for proper opera-
tion of the heating and air conditioning systems.
INSTALLATION - HVAC HOUSING INLET
BAFFLE
(1) Install the HVAC housing inlet baffle in the
cowl plenum panel.
(2) Slide the HVAC housing inlet baffle to engage
the snap features.
(3) Make certain that the snap features on each
side of the adapter are fully engaged with the sides
of the plenum panel opening. This must be a water
tight connection to prevent leaks.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
INSTRUMENT PANEL
DEMISTER DUCTS
REMOVAL
The defroster duct and the main demister duct are
a single molded plastic unit. The defroster outlet
grilles are heat-staked to the defroster outlets and
cannot be serviced separately. The demister tubes on
each end of the main demister duct are only serviced
in the instrument panel assembly. (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL)
INSTALLATION
The defroster duct and the main demister duct are
a single molded plastic unit. The defroster outlet
grilles are heat-staked to the defroster outlets and
cannot be serviced separately. The demister tubes on
each end of the mail demister duct are only serviced
in the instrument panel assembly(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - INSTALLATION).
24 - 36 DISTRIBUTIONBR/BE
HVAC HOUSING (Continued)

EMISSIONS CONTROL
TABLE OF CONTENTS
page page
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - DIESEL.................1
DESCRIPTION - STATE DISPLAY TEST
MODE...............................1
DESCRIPTION - CIRCUIT ACTUATION TEST
MODE...............................2
DESCRIPTION - DIAGNOSTIC TROUBLE
CODES..............................2
DESCRIPTION - TASK MANAGER.........17
DESCRIPTION - MONITORED SYSTEMS . . . 17
DESCRIPTION - TRIP DEFINITION........19
DESCRIPTION - COMPONENT MONITORS -
GAS ENGINES.......................19DESCRIPTION - COMPONENT MONITORS -
DIESEL ENGINES.....................20
OPERATION
OPERATION - GAS ENGINES............20
OPERATION - DIESEL..................20
OPERATION - TASK MANAGER..........21
OPERATION - NON-MONITORED
CIRCUITS - GAS ENGINES..............24
OPERATION - NON-MONITORED
CIRCUITS - DIESEL....................24
AIR INJECTION.........................26
EVAPORATIVE EMISSIONS................32
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - DIESEL
Two different modules are used for powertrain con-
trol with the diesel engine. The Powertrain Control
Module (PCM) is used primarily for charging system,
transmission, A/C compressor clutch operation and
speed control functions. The Engine Control Module
(ECM) is used to control thefuel and emissions
systems.The PCM is located in the right/rear of
engine compartment (Fig. 1). The ECM is bolted to
the left side of the engine cylinder block (Fig. 2).
DESCRIPTION - STATE DISPLAY TEST MODE
The switch inputs to the Powertrain Control Mod-
ule (PCM) have two recognized states; HIGH and
LOW. For this reason, the PCM cannot recognize the
difference between a selected switch position versus
an open circuit, a short circuit, or a defective switch.
If the State Display screen shows the change from
HIGH to LOW or LOW to HIGH, assume the entire
switch circuit to the PCM functions properly. Connectthe DRB scan tool to the data link connector and
access the state display screen. Then access either
State Display Inputs and Outputs or State Display
Sensors.
Fig. 1 Powertrain Control Module (PCM) Location
1 - PCM MOUNTING BOLTS (3)
2 - POWERTRAIN CONTROL MODULE (PCM)
3 - (3) 32±WAY CONNECTORS
BR/BEEMISSIONS CONTROL 25 - 1

DESCRIPTION - CIRCUIT ACTUATION TEST
MODE
The Circuit Actuation Test Mode checks for proper
operation of output circuits or devices the Powertrain
Control Module (PCM) may not internally recognize.
The PCM attempts to activate these outputs and
allow an observer to verify proper operation. Most of
the tests provide an audible or visual indication of
device operation (click of relay contacts, fuel spray,
etc.). Except for intermittent conditions, if a device
functions properly during testing, assume the device,its associated wiring, and driver circuit work cor-
rectly. Connect the DRB scan tool to the data link
connector and access the Actuators screen.
DESCRIPTION - DIAGNOSTIC TROUBLE CODES
A Diagnostic Trouble Code (DTC) indicates the
PCM has recognized an abnormal condition in the
system.
Remember that DTC's are the results of a sys-
tem or circuit failure, but do not directly iden-
tify the failed component or components.
NOTE: For a list of DTC's, refer to the charts in this
section.
BULB CHECK
Each time the ignition key is turned to the ON
position, the malfunction indicator (check engine)
lamp on the instrument panel should illuminate for
approximately 2 seconds then go out. This is done for
a bulb check.
OBTAINING DTC'S USING DRB SCAN TOOL
(1) Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located in
the passenger compartment; at the lower edge of
instrument panel; near the steering column.
(2) Turn the ignition switch on and access the
ªRead Faultº screen.
(3) Record all the DTC's and ªfreeze frameº infor-
mation shown on the DRB scan tool.
(4) To erase DTC's, use the ªErase Trouble Codeº
data screen on the DRB scan tool.Do not erase any
DTC's until problems have been investigated
and repairs have been performed.
Fig. 2 Engine Control Module (ECM) Location
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - FUEL TRANSFER PUMP
4 - MOUNTING BOLTS (3)
5 - 50±WAY CONNECTOR
25 - 2 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P0307 (M) CYLINDER #7 MISFIRE Misfire detected in cylinder #7
P0308 (M) CYLINDER #8 MISFIRE Misfire detected in cylinder #8.
P0309 (M) CYLINDER #9 MISFIRE Misfire detected in cylinder #9.
P0310 (M) CYLINDER #10 MISFIRE Misfire detected in cylinder #10.
P0320 (M) No Crank Referance Signal at PCM No reference signal (crankshaft position sensor) detected
during engine cranking.
P0320 (M) No RPM Signal to PCM (Crankshaft
Position Sensor Signal to JTEC)A CKP signal has not been detected at the PCM.
P0325 Knock Sensor #1 Circuit Knock sensor (#1) signal above or below minimum
acceptable threshold voltage at particular engine speeds.
P0330 Knock Sensor #2 Circuit Knock sensor (#2) signal above or below minimum
acceptable threshold voltage at particular engine speeds.
P0336 (M) Crankshaft Position (CKP) Sensor
SignalProblem with voltage signal from CKP.
P0340 (M) No Cam Signal At PCM No fuel sync
P0341 (M) Camshaft Position (CMP) Sensor
SignalProblem with voltage signal from CMP.
P0350 Ignition Coil Draws Too Much Current A coil (1-5) is drawing too much current.
P0351 (M) Ignition Coil # 1 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time.
P0352 (M) Ignition Coil # 2 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time.
P0353 (M) Ignition Coil # 3 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time.
P0354 (M) Ignition Coil # 4 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time (High Impedance).
P0355 (M) Ignition Coil # 5 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time (High Impedance).
P0356 (M) Ignition Coil # 6 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time (high impedance).
P0357 (M) Ignition Coil # 7 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time (high impedance).
P0358 (M) Ignition Coil # 8 Primary Circuit Peak primary circuit current not achieved with maximum
dwell time (high impedance).
P0370 Fuel Injection Pump Speed/Position
Sensor Sig LostProblem caused by internal fuel injection pump failure.
P0380 (M) Intake Air Heater Relay #1 Control
CircuitProblem detected in #1 air heater solenoid/relay circuit (not
heater element)
P0381 (M) Wait To Start Lamp Inoperative Problem detected in wait-to-start bulb circuit.
P0382 (M) Intake Air Heater Relay #2 Control
CircuitProblem detected in #2 air heater solenoid/relay circuit (not
heater element)
P0387 Crankshaft Position Sensor Supply
Voltage Too LowCKP sensor voltage input below the minimum acceptable
voltage.
BR/BEEMISSIONS CONTROL 25 - 7
EMISSIONS CONTROL (Continued)

(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P0388 Crankshaft Position Sensor Supply
Voltage Too HighCKP sensor voltage input above the maximum acceptable
voltage.
PO0400 Diesel EGR System Failure
P0401 EGR System Failure Required change in air/fuel ration not detected during
diagnostic test.
P0403 EGR Solenoid Circuit An open or shorted condition detected in the EGR solenoid
control circuit.
P0404 EGR Position Sensor Rationality EGR position sensor signal does not correlate to EGR duty
cycle.
P0405 EGR Position Sensor Volts Too Low EGR position sensor input below the acceptable voltage
range.
P0406 EGR Position Sensor Volts Too High EGR position sensor input above the acceptable voltage
range.
P0412 Secondary Air Solenoid Circuit An open or shorted condition detected in the secondary air
(air switching/aspirator) solenoid control circuit.
P0420 (M) 1/1 Catalytic Converter Efficiency Catalyst 1/1 efficiency below required level.
P0432 (M) 1/2 Catalytic Converter Efficiency Catalyst 2/1 efficiency below required level.
P0441 (M) Evap Purge Flow Monitor Insufficient or excessive vapor flow detected during
evaporative emission system operation.
P0442 (M) Evap Leak Monitor Medium Leak
DetectedA small leak has been detected in the evaporative system.
P0443 (M) Evap Purge Solenoid Circuit An open or shorted condition detected in the EVAP purge
solenoid control circuit.
P0455 (M) Evap Leak Monitor Large Leak
DetectedA large leak has been detected in the evaporative system.
P0456 (M) Evap Leak Monitor Small Leak
DetectedLeak has been detected in the evaporative system.
P0460 Fuel Level Unit No Change Over Miles During low fuel
P0460 Fuel Level Unit No Change Over Miles Fuel level sending unit voltage does not change for more
than 40 miles.
PO061 Fuel Level Unit No Change Over Time
P0462 Fuel Level Sending Unit Volts Too Low Fuel level sensor input below acceptable voltage.
P0462 (M) Fuel Level Sending Unit Volts Too Low Open circuit between PCM and fuel gauge sending unit.
P0463 Fuel Level Sending Unit Volts Too
HighFuel level sensor input above acceptable voltage.
P0463 (M) Fuel Level Sending Unit Volts Too
HighCircuit shorted to voltage between PCM and fuel gauge
sending unit.
P0500 (M) No Vehicle Speed Sensor Signal No vehicle speed sensor signal detected during road load
conditions.
P0500 (M) No Vehicle Speed Sensor Signal A vehicle speed signal was not detected.
P0505 (M) Idle Air Control Motor Circuits
P0508 (M) IAC Motor Sense Circuit Low
25 - 8 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P0509 (M) IAC Motor Sense Circuit High
P0521 Oil Pressure Switch Rationality
P0522 Oil Pressure Voltage Too Low Oil pressure sending unit (sensor) voltage input below the
minimum acceptable voltage.
P0523 Oil Pressure Voltage Too High Oil pressure sending unit (sensor) voltage input above the
maximum acceptable voltage.
P0524 Oil Pressure Too Low Engine oil pressure is low. Engine power derated.
P0545 A/C Clutch Relay Circuit Problem detected in air conditioning clutch relay control
circuit.
P0551 Power Steering Switch Failure Incorrect input state detected for the power steering switch
circuit. PL: High pressure seen at high speed.
P0562 Charging System Voltage Too Low Supply voltage sensed at ECM too low.
P0563 Charging System Voltage Too High Supply voltage sensed at ECM too high.
P0572 Brake Switch Input #1 Signal Missing
P0573 Brake Switch Input #2 Signal Missing
P0575 Cruise Control Switch Voltage Low
P0576 Cruise Control Switch Voltage High
P0577 Cruise Control Switch Voltage High
P0600 PCM Failure SPI Communications No communication detected between co-processors in the
control module.
P0601 (M) Internal Controller Failure Internal control module fault condition (check sum) detected.
P0602 (M) ECM Fueling Calibration Error ECM Internal fault condition detected.
P0604 RAM Check Failure Transmission control module RAM self test fault detected.
-Aisin transmission
P0605 ROM Check Falure Transmission control module ROM self test fault detected
-Aisin transmission
P0606 (M) ECM Failure ECM Internal fault condition detected.
P0615 Starter Relay Control Circuit An open or shorted condition detected in the starter relay
control circuit.
P0622 (G) Generator Field Not Switching Properly An open or shorted condition detected in the generator field
control circuit.
P0645 A/C Clutch Relay Circuit An open or shorted condition detected in the A/C clutch relay
control circuit.
P0700 EATX Controller DTC Present This SBEC III or JTEC DTC indicates that the EATX or Aisin
controller has an active fault and has illuminated the MIL via
a CCD (EATX) or SCI (Aisin) message. The specific fault
must be acquired from the EATX via CCD or from the Aisin
via ISO-9141.
P0703 Brake Switch Stuck Pressed or
ReleasedIncorrect input state detected in the brake switch circuit.
(Changed from P1595)
P0703 Brake Switch Sense Circuit
BR/BEEMISSIONS CONTROL 25 - 9
EMISSIONS CONTROL (Continued)

(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P1290 High Pressure Solenoid Relay Ckt. CNG Fuel System Pressure Too High±Compressed natural
gas system pressure above normal operating range.
P1291 No Temp Rise Seen From Intake
HeatersEnergizing Heated Air Intake does not change intake air
temperature sensor an acceptable amount.
P1291 (M) No Temperature Rise Seen From
Intake Air HeatersProblem detected in intake manifold air heating system.
P1292 CNG Pressure Sensor Voltage Too
HighCompressed natural gas pressure sensor reading above
acceptable voltage.
P1293 CNG Pressure Sensor Voltage Too
LowCompressed natural gas pressure sensor reading below
acceptable voltage.
P1294 (M) Target Idle Not Reached Target RPM not achieved during drive idle condition.
Possible vacuum leak or IAC (AIS) lost steps.
P1295 (M) No 5 Volts to TP Sensor Loss of a 5 volt feed to the Throttle Position Sensor has
been detected.
P1295 (M) Accelerator Position Sensor (APPS)
Supply Voltage Too LowAPPS supply voltage input below the minimum acceptable
voltage.
P1296 No 5 Volts to MAP Sensor Loss of a 5 volt feed to the MAP Sensor has been detected.
P1297 (M) No Change in MAP From Start To Run No difference is recognized between the MAP reading at
engine idle and the stored barometric pressure reading.
P1298 Lean Operation at Wide Open Throttle A prolonged lean condition is detected during Wide Open
Throttle
P1299 Vacuum Leak Found (IAC Fully
Seated)MAP Sensor signal does not correlate to Throttle Position
Sensor signal. Possible vacuum leak.
P1388 Auto Shutdown Relay Control Circuit An open or shorted condition detected in the ASD or CNG
shutoff relay control ckt.
P1388 Auto Shutdown Relay Control Circuit An open or shorted condition detected in the auto shutdown
relay circuit.
P1389 No ASD Relay Output Voltage At PCM No Z1 or Z2 voltage sensed when the auto shutdown relay is
energized.
P1389 (M) No ASD Relay Output Voltage at PCM An open condition detected In the ASD relay output circuit.
P1390 Timing Belt Skipped 1 Tooth or More Relationship between Cam and Crank signals not correct
P1391 (M) Intermittent Loss of CMP or CKP Loss of the Cam Position Sensor or Crank Position sensor
has occurred. For PL 2.0L
P1398 (M) Mis-Fire Adaptive Numerator at Limit PCM is unable to learn the Crank Sensor's signal in
preparation for Misfire Diagnostics. Probable defective Crank
Sensor
P1399 Wait To Start Lamp Cicuit An open or shorted condition detected in the Wait to Start
Lamp circuit.
P1403 No 5V to EGR Sensor Loss of 5v feed to the EGR position sensor.
P01475 Aux 5 Volt Supply Voltage High Sensor supply voltage for ECM sensors is too high.
P1476 Too Little Secondary Air Insufficient flow of secondary air injection detected during
aspirator test (was P0411)
25 - 12 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P1496 5 Volt Supply, Output Too Low 5 volt sensor feed is sensed to be below an acceptable limit.
( less than 4v for 4 sec )
P1498 High Speed Rad Fan Ground CTRL
Rly CircuitAn open or shorted condition detected in the control circuit of
the #3 high speed radiator fan control relay.
P1499 Hydraulic cooling fan solenoid circuit An open or shorted condition detected in the cooling fan
control solenoid circuit.
P1594 (G) Charging System Voltage Too High Battery voltage sense input above target charging voltage
during engine operation.
P1594 Charging System Voltage Too High Battery voltage sense input above target charging voltage
during engine operation.
P1595 Speed Control Solenoid Circuits An open or shorted condition detected in either of the speed
control vacuum or vent solenoid control circuits.
P1595 Speed Control Solenoid Circuits An open or shorted condition detected in the speed control
vacuum or vent solenoid circuits.
P1596 Speed Control Switch Always High Speed control switch input above maximum acceptable
voltage.
P1597 Speed Control Switch Always Low Speed control switch input below minimum acceptable
voltage.
P1597 Speed Control Switch Always Low Speed control switch input below the minimum acceptable
voltage.
P1598 A/C Pressure Sensor Volts Too High A/C pressure sensor input above maximum acceptable
voltage.
P1598 A/C Sensor Input Hi Problem detected in air conditioning electrical circuit.
P1599 A/C Pressure Sensor Volts Too Low A/C pressure sensor input below minimum acceptable
voltage.
P1599 A/C Sensor Input Lo Problem detected in air conditioning electrical circuit.
P1602 PCM not programmed
P1680 Clutch Released Switch Circuit Problem detected in clutch switch electrical circuit.
P1681 No I/P Cluster CCD/J1850 Messages
ReceivedNo CCD/J1850 messages received from the cluster control
module.
P1682 (G) Charging System Voltage Too Low Battery voltage sense input below target charging voltage
during engine operation and no significant change in voltage
detected during active test of generator output circuit.
P1682 Charging System Voltage Too Low Charging system output voltage low.
P1683 SPD CTRL PWR Relay; or S/C 12v
Driver CKTAn open or shorted condition detected in the speed control
servo power control circuit.
P1683 Spd ctrl pwr rly, or s/c 12v driver circuit An open or shorted condition detected in the speed control
servo power control circuit.
P1684 Batt Loss (disconnected) in last 50
StartsThe battery has been disconnected within the last 50 starts
P1685 SKIM Invalid Key - (Wrong or Invalid
Key MSG Received From SKIM)The engine controler has received an invalid key from the
SKIM.
25 - 14 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)