1999 DODGE RAM PCM ground

“O” ABBREVIATION TABLE (con’t) ABBREVIATION DEFINITION OHC Overhead Camshaft ORG Orange OSC Output State Check Opt. Option or Optional oz. Ounce ozs. Ounces

"P" ABBREVIATION TABLE

"P" ABBREVIATION TABLE
ABBREVIATION DEFINITION P Park P/C Printed Circuit P/N Park/Neutral P/S Power Steering PAV Pulse Air Valve PC-SOL Purge Control Solenoid PCM Powertrain Control module PCS Purge Control Solenoid PCSDM Passenger Compartment Sensor/Diagnostic Module PCV Positive Crankcase Ventilation PFE Pressure Feedback EGR sensor or circuit PFI Port Fuel Injection (see MA SEFI) PGM-CARB Programmed Carburetor PGM-FI Programmed Fuel Injection PIP Profile Ignition Pickup PNK Pink PPL Purple PRNDL Park Reverse Neutral Drive Low PROM Programmable Read-Only Memory psi Pounds Per Square Inch PSPS Power Steering Pressure Switch PTC Positive Temperature Coefficient PTO Power Take-Off PWR GND Power Ground circuit Pkg. Package Press. Pressure Prog. Programmed or Programmable Pts. Pints Pwr. Power

"Q" ABBREVIATION TABLE
"Q" ABBREVIATION TABLE
ABBREVIATION DEFINITION Qts.
Quarts

OPERATION
CONTROL PANEL
Blower Motor Switch
Fan speed is controlled with a rotary switch. On front A/C-
heater systems, there are 4 different fan speed settings. Low, medium-
low, medium-high, and high. On rear A/C-heater systems, there are 3
different fan speed settings. Low, medium, and high.
Mode Control Knob
Mode rotary switch is used to change direction of air flow.
There are 7 different modes of operation: recirculation, panel with
A/C, floor/panel, panel without A/C (vent), floor, floor/defrost, and
defrost.
Temperature Control Knob
Temperature rotary switch controls temperature blend/air door
position by a cable on Dakota and Durango, and by vacuum actuator for
Ram Pickup. When cold temperature is selected, no air flows across
heater core. When hot temperature is selected, all air flows through
heater core. Temperature may vary by any setting between cold and hot.
CLUTCH CYCLING PRESSURE SWITCH
Dakota & Ram Pickup
Clutch cycling low pressure switch is mounted on a Schrader-
type valve fitting that is part of the accumulator. It is connected in
series with the high pressure cut-off switch and control panel,
between ground and PCM. Switch contacts open and close due to changes
in A/C system pressure. Opening and closing of switches will cause PCM
to turn compressor clutch on and off, regulating system pressure which
controls temperature of evaporator.
Clutch cycling low pressure switch contacts are normally open
when suction (low side) pressure drops below 25 psi (1.8 kg/cm
) on
Ram Pickup; 20.5 psi (1.4 kg/cm) on Dakota. Extreme cold weather will
also open contacts. When contacts are open, PCM will de-energize
compressor clutch relay, disengaging compressor clutch.
Clutch cycling pressure switch contacts will close when
suction (low side) pressure rises above 43 psi (3.0 kg/cm
) on Ram
Pickup or 36 psi (2.5 kg/cm) on Dakota. When contacts are closed, PCM
will energize compressor clutch relay, engaging compressor clutch.
ELECTRONIC CYCLING CLUTCH SWITCH
Durango
The electronic cycling clutch switch is mounted to Thermal
Expansion Valve (TXV), also referred to as an "H" valve, in engine
compartment. It provides evaporator temperature to the PCM. Using this
information, the PCM will cycle the compressor clutch to prevent
evaporator icing. The switch is used for the front evaporator only.
Electronic cycling clutch switch is connected in series with
mode control switch, high pressure cut-out switch, low pressure cut-
out switch, and PCM. The electronic cycling clutch switch opens when
refrigerant temperature is below about 37
F (2.8C) and will close
when refrigerant temperature is about 40F (4.4C).
FIXED ORIFICE TUBE
Dakota & Ram Pickup
The fixed orifice tube is located in outlet line of the
condenser. The orifice tube inlet and outlet ends have a screen to

filter the refrigerant. The orifice tube is used to meter the flow of
liquid refrigerant into the evaporator core.
HIGH PRESSURE CUT-OUT SWITCH
High pressure cut-out switch is located on compressor
discharge line, near compressor. On Dakota and Ram Pickup, it is
connected in series with the clutch cycling pressure switch and
control panel, between ground and PCM.
On Durango, it is connected in series with the electronic
cycling clutch switch, low pressure cut-out switch and control panel,
between ground and PCM. PCM controls compressor clutch operation.
On all models, when discharge pressure reaches 450-490 psi
(31.6-34.5 kg/cm
), high pressure cut-out switch interrupts A/C
request signal to PCM. PCM de-energizes compressor clutch relay,
disengaging compressor clutch. When discharge pressure drops to 270-
330 psi (23.2-19 kg/cm
) switch will close, thus restoring A/C request
signal to PCM.
HIGH PRESSURE RELIEF VALVE
High pressure relief valve is located on compressor manifold.
Valve vents system pressure if pressure is greater than 500-600 psi
(35.1-42.2 kg/cm
). Valve will reset when pressure decreases to 400
psi (28.1 kg/cm).
LOW PRESSURE CUT-OUT SWITCH OPERATION
Durango
Low pressure cut-out switch is located on suction line near
firewall. It is connected in series with the electronic cycling clutch
switch, high pressure cut-out switch and control panel, between ground
and PCM. PCM controls compressor clutch operation.
When discharge pressure reaches 10 psi (.7 kg/cm
), switch
interrupts A/C request signal to PCM. PCM de-energizes compressor
clutch relay, disengaging compressor clutch. When discharge pressure
increases to 13-27 psi (.9-1.9 kg/cm
), switch will close thus
restoring A/C request signal to PCM.
ADJUSTMENTS
TEMPERATURE CONTROL CABLE ADJUSTMENT
Dakota & Durango
1) Ensure temperature control cable housing and core are
connected at both A/C-heater control panel and A/C-heater assembly.
Ensure A/C-heater control panel is installed.
2) Rotate temperature control knob so that knob pointer is at
12 o'clock position. Pull temperature control knob straight out from
A/C-heater control panel until perimeter of knob (not knob pointer)
protrudes about .25" (6 mm) from face of A/C-heater control panel.
3) Rotate temperature control knob clockwise so that knob
pointer is at one o'clock position. Push in on knob slightly and
continue rotating knob to its full clockwise stop. Place knob pointer
at a position about .32" (8 mm) beyond end of Red stripe. Release
knob. If knob is pointing at about .32" (8 mm) beyond end of Red
stripe, go to next step. If knob is not pointing at about .32" (8 mm)
beyond end of Red stripe, go back to step 2) and repeat adjustment
procedure.
4) Rotate temperature control knob counterclockwise so that
knob pointer is at 12 o'clock position. Push temperature control knob
straight into A/C-heater control panel until perimeter of knob (not

connector terminal No. 14 (Light Green/Yellow wire). If voltage is
less than 10 volts, repair open in Light Green/Yellow wire. If voltage
is more than 10 volts, replace ACM.
4) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
5) Turn ignition off. Turn PAD switch to the ON position (if
equipped). Using an ohmmeter, check resistance at fused ignition
switch output RUN/START circuit between fuse No. 19 and ground. If
resistance is more than 5 ohms, replace fuse. If resistance is less
than 5 ohms, disconnect battery and wait 2 minutes before proceeding.
Disconnect ACM connector. Using an ohmmeter, check resistance between
ground and ACM connector terminal No. 14 (Light Green/Yellow wire). If\
resistance is less than 5 ohms, go to next step. If resistance is more
than 5 ohms, replace ACM and fuse No. 19.
6) Disconnect PAD switch. Using an ohmmeter, check resistance
between ground and ACM connector terminal No. 14 (Light Green/Yellow
wire). If resistance is less than 5 ohms, repair short to ground in
Light Green/Yellow wire and replace fuse No. 19. If resistance is more
than 5 ohms, replace fuse No. 19 located in junction block and go to
next step.
7) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
MISSING OR INVALID VIN MESSAGE
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using DRB, select ENGINE PCM. If DRB displays NO RESPONSE
from PCM, go to NO RESPONSE FROM POWERTRAIN CONTROL MODULE under
VEHICLE COMMUNICATIONS. If DRB does not display NO RESPONSE from PCM
and vehicle is a Club Cab (BE) model, go to next step. If vehicle is
not a Club Cab (BE model), go step 3).
2) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITORS.
Select VIN type (7th digit of VIN; VIN 2 or 3 on Club Cab). If DRB
does not display PCM VIN: BE, replace Powertrain Control Module (PCM).\
If DRB displays PCM VIN: BE, replace ACM.
3) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITORS.
Select VIN type (7th digit of VIN; VIN 6 on Standard Cab). If DRB does\
not display PCM VIN: BR, replace Powertrain Control Module (PCM). If
DRB displays PCM VIN: BR, replace ACM.
NO CCD COMMUNICATION
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
Using DRB, read active codes. If DRB displays NO CCD
COMMUNICATION as an active code, replace ACM. If DRB does not display
NO CCD COMMUNICATION as an active code, go to
REPAIRING STORED TROUBLE CODES .
NO CLUSTER CCD MESSAGE

6) Using DRB in voltmeter mode, check voltage at ACM
connector terminal No. 22 (White/Black wire). If voltage is 1.8-2.6
volts, replace ACM. If voltage is not 1.8-2.6 volts, repair open in
White/Black wire.
OPEN FUSED IGNITION SWITCH OUTPUT (RUN/START) CKT
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Turn ignition on (engine off). Using DRB in voltmeter
mode, probe output side (Dark Blue wire) of fuse No. 19 located in
junction block. If voltage is less than 10 volts, repair open in Dark
Blue wire. If voltage is more than 10 volts, go to next step.
2) Turn ignition off and wait 2 minutes before proceeding.
Using DRB in ohmmeter mode, probe fused side (Light Green/Yellow wire)\
of fuse No. 19 located in junction block. If resistance is less than 5
ohms, go to next step. If resistance is more than 5 ohms, go to step
4).
3) Disconnect ACM connector. Using DRB in ohmmeter mode,
probe fused side (Light Green/Yellow wire) of fuse No. 19 located in
junction block. If resistance is less than 5 ohms, repair short to
ground in Light Green/Yellow wire an replace fuse No. 19. If
resistance is more than 5 ohms, replace ACM and fuse No. 19.
4) Turn ignition off and wait 2 minutes before proceeding.
Disconnect ACM. Using an ohmmeter, check resistance between ACM
connector terminal No. 14 (Light Green/Yellow wire) and fused side
(Light Green/Yellow wire) of fuse No. 19 located in junction block. If\
resistance is more than 5 ohms, repair open in Light Green/Yellow wire
and replace fuse No. 19. If resistance is less than 5 ohms, go to next
step.
5) Reconnect ACM connector. Turn ignition on (engine off).
replace fuse No. 19. Perform appropriate diagnostic test under
DIAGNOSTIC TESTS.
NO RESPONSE FROM POWERTRAIN CONTROL MODULE
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) If engine does not run, repair as required. If engine
runs, disconnect Powertrain Control Module (PCM) connectors. Connect a\
jumper wire between ground and PCM Gray connector terminal C30
(Violet/Brown wire). Using DRB, perform CCD bus test. If DRB does not
display SHORT TO GROUND, repair open Violet/Brown wire. If DRB
displays SHORT TO GROUND, go to next step.
2) Connect a jumper wire between ground and PCM Gray
connector terminal C28 (White/Black wire). Using DRB, perform CCD bus
test. If DRB does not display SHORT TO GROUND, repair open White/Black
wire. If DRB displays SHORT TO GROUND, replace PCM.
REPAIRING SHORT TO BATTERY
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,

inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Ensure ignition switch is in the RUN position. Disconnect
Powertrain Control Module (PCM) connectors. If DRB does not display
BUS SHORT TO BATTERY, to step 8). If DRB displays BUS SHORT TO
BATTERY, go to next step.
2) Disconnect instrument cluster connectors. If DRB does not
display BUS SHORT TO BATTERY, replace instrument cluster. If DRB
displays BUS SHORT TO BATTERY, go to next step.
3) Turn ignition off and wait 2 minutes before proceeding.
Disconnect air bag control module connector. Turn ignition on (engine
off). If DRB does not display SHORT TO BATTERY, replace ACM. If DRB
displays SHORT TO BATTERY, go to next step.
4) Disconnect Central Timer Module (CTM) 18-pin connector. I\
f
DRB does not display BUS SHORT TO BATTERY, replace CTM. If DRB
displays BUS SHORT TO BATTERY, go to next step.
5) Disconnect anti-lock brake controller. If DRB does not
display BUS SHORT TO BATTERY, replace anti-lock brake controller. If
DRB displays BUS SHORT TO BATTERY, go to next step.
6) Disconnect DRB from Data Link Connector (DLC). Using a
voltmeter, check voltage between ground and DLC connector terminal No.
3 (Violet/Brown wire). If voltage is more than 0.2 volt, repair short
in Violet/Brown wire. If voltage is less than 0.2 volt, go to next
step.
7) Using a voltmeter, check voltage between ground and DLC
connector terminal No. 11 (White/Black wire). If voltage is more than
0.2 volt, repair short in White/Black wire. If voltage is less than 0.
2 volt, replace DRB or DRB cable as necessary.
8) Turn ignition off. Using an ohmmeter, check resistance
between ground and PCM Black connector terminal A31 (Black/Tan wire).
If resistance is more than 10 ohms, repair open in Black/Tan wire). If
resistance is less than 10 ohms, go to next step.
9) Using an ohmmeter, check resistance between ground and PCM
Black connector terminal A32 (Black/Tan wire). If resistance is more
than 10 ohms, repair open in Black/Tan wire). If resistance is less
than 10 ohms, replace Powertrain Control Module (PCM).
NO RESPONSE FROM INSTRUMENT CLUSTER
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Remove Instrument cluster. Using DRB, turn on INTERNAL BUS
BIAS under SYSTEM MONITORS CCD BUS VOLTAGE. Connect a jumper wire from
Black instrument cluster 10-pin connector "A" terminal No. 9
(White/Black wire) to ground. Observe CCD BUS voltage on DRB. If
voltage did not drop to about zero volt, repair open in White/Black
wire. If voltage drops to about zero volt, go to next step.
2) Leave internal DRB CCD BUS BIAS turned on. Connect a
jumper wire from ground to Black instrument cluster 10-pin connector
"A" terminal No. 10 (Violet/Brown wire). Go to next step.
3) Observe CCD BUS voltage on DRB. If voltage did not drop to
about zero volt, repair open in Violet/Brown wire. If voltage drops to
about zero volt, replace instrument cluster.

The PCM contains a self-diagnostic system used for
determining an electronic component failure. The PCM self-diagnostic
system will store a Diagnostic Trouble Code (DTC) in PCM memory if
certain electronic problems are present.
DTCs can be retrieved using appropriate scan tool. See SELF-
DIAGNOSTIC SYSTEM. After repairing an electronic system problem,
stored DTC must be cleared from PCM memory. For PCM location, see PCM
LOCATION table.
AB Body
On firewall, near wiper motor.
AN & DN Bodies
Right front fender, near air cleaner.
BR Body
Right front fender, near firewall.
WJ Body
On firewall, near speed control servo.
GOVERNOR PRESSURE SENSOR
NOTE: Governor pressure sensor may also be referred to as governor
pressure transducer.
Governor pressure sensor delivers an output signal to the PCM
indicating the output pressure of governor pressure solenoid. The PCM
uses this signal to control governor pressure. Governor pressure
solenoid is located on valve body. See Fig. 1.
GOVERNOR PRESSURE SOLENOID
Governor pressure solenoid generates governor pressure
required for transmission upshifts and downshifts. Governor pressure
solenoid is located on valve body. See Fig. 1. Inlet side of governor
pressure solenoid is exposed to normal transmission line pressure and
outlet side provides a passage to governor circuit in the valve body.
Governor pressure solenoid regulates transmission line pressure to the
governor circuit. Electrical supply voltage is supplied to governor
pressure solenoid by PCM. The PCM controls the ground circuit to
governor pressure solenoid to provide solenoid operation.
Fig. 1: Identifying Governor Pressure Solenoid, Governor Pressure
Sensor & Transmission Fluid Temperature Sensor
Courtesy of DaimlerChrysler Corp.
OD (OVERDRIVE) OFF SWITCH

stretched, cut or pinched wiring. Ensure electrical connectors fit
tightly and are not corroded. Check PCM, sensors and switches for
physical damage. Check engine coolant level. Check transmission fluid
level and condition.
SELF-DIAGNOSTIC SYSTEM
* PLEASE READ THIS FIRST *
NOTE: Only transaxle-related trouble codes are listed. For engine-
related DTC definitions, see TROUBLE CODE DEFINITIONS article
in APPLICATIONS & IDENTIFICATION. For engine-related DTC
diagnosis, see appropriate SELF-DIAGNOSTICS article in ENGINE
PERFORMANCE. Engine performance DTCs must be repaired first,
as engine performance and related component signals will
affect transaxle operation and diagnosis.
DIAGNOSTIC PROCEDURE
When performing vehicle diagnosis:
* Ensure transmission fluid level is correct and fluid is
neither contaminated or aerated.
* Ensure shift cable is properly adjusted. See appropriate
AUTOMATIC TRANSMISSION SERVICING article in TRANSMISSION
SERVICING.
* Ensure battery is fully charged.
* Perform visual inspection, ensuring all electrical
connections at transmission, PCM, TP sensor and output shaft
speed sensor are clean and properly installed.
* Retrieve DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES.
* Repair DTCs in order displayed.
* Always perform test verification test after any repair
procedure is completed unless specified otherwise. See
appropriate verification test under DIAGNOSTIC TESTS.
NOTE: Self-diagnostic tests are written specifically for Chrysler's
Diagnostic Readout Box (DRB) scan tool. A generic scan tool
may be used, but may not be capable of performing all
necessary test functions.
TEST EQUIPMENT HOOK-UP
Generic Scan Tool & DVOM
Self-diagnostic tests are written specifically for Chrysler's
Diagnostic Readout Box (DRB) scan tool. The DRB has a built-in DVOM
function. A generic scan tool may be used, but may not be capable of
performing all necessary test functions. If DRB test procedures
require resistance or voltage to be measured using scan tool in
ohmmeter or voltmeter mode, connect DVOM ground lead to DLC connector
terminal No. 4 and positive lead to terminal specified in test
procedure.
DRB Scan Tool
Refer to DRB scan tool instructions to read and clear DTCs,
and when performing other scan tool functions. DRB scan tool is
grounded through DLC connector terminal No. 4. Only one volt/ohmmeter
test lead is required to measure voltage or resistance. See Fig. 2.
RETRIEVING DIAGNOSTIC TROUBLE CODES
NOTE: Manufacturer recommends using Chrysler's Diagnostic Readout