Contents

Wiring diagrams Section: Testing & Diagnostics

O2 Sensor Location & Identification

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Engine Controls - System & Component Testing - Gasoline: Other Dodge Pickup R1500

Testing & Diagnostics 16 illustrations ~4469 words

POWERTRAIN CONTROL MODULE

Note. If replacing Powertrain Control Module (PCM), the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Air Bag Control Module (ACM).

Connect scan tool to Data Link Connector (DLC) located below instrument panel, near steering column. Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from CAB module and ACM.

Checking PCM Power & Ground Circuits

For testing procedures (Scheme 1020) For PCM connector identification, see CONNECTOR IDENTIFICATION. For circuit identification, see WIRING DIAGRAMS.

Scheme 1020

Scheme 1020: Checking PCM Power & Ground Circuits

SENSORS & SWITCHES

Note. Diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRBIII®) scan tool. A generic scan tool may not be capable of performing all necessary test functions.

BRAKE SWITCH

Disconnect brake switch 6-pin connector. Using an ohmmeter, check for continuity at brake switch. (Scheme 1021) If continuity is not as specified in BRAKE SWITCH CONTINUITY table, replace defective brake switch.

Switch Plunger Position	Continuity Between Terminals No.
Depressed	1 & 2
Released	3 & 4; 5 & 6

BRAKE SWITCH CONTINUITY

Scheme 1021

BRAKE SWITCH SENSE STATUS DOES NOT CHANGE ON DRBIII® (RAM VAN)

For PCM connector identification, see CONNECTOR IDENTIFICATION . For circuit identification, see WIRING DIAGRAMS .

For testing procedures (Scheme 1022)and (Scheme 1023).

Scheme 1022

Scheme 1022: BRAKE SWITCH SENSE STATUS DOES NOT CHANGE ON DRBIII® (RAM VAN)

Scheme 1023

CAMSHAFT POSITION SENSOR

Individual component testing is not available. For Camshaft Position (CMP) sensor testing, see the following

For Ram Pickup, see «DTC P0340: NO CAM SIGNAL AT PCM»(ref-157055-S04861602272003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see «DTC P0340: CAMSHAFT POSITION SENSOR CIRCUIT»(ref-157234-S02512835802003080700000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - RAM PICKUP - 4.7L & 5.7L article.
For Ram Van, see «DTC P0340: NO CAM REFERENCE SIGNAL AT PCM»(ref-157603-S34042000402003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

CRANKSHAFT POSITION SENSOR

Individual component testing is not available. For Crankshaft Position (CKP) sensor testing, see the following

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM»(ref-157055-S32157659622003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see «DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT»(ref-157234-S32268343592003080800000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - RAM PICKUP - 4.7L & 5.7L article.
For Ram Van, see «DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM»(ref-157603-S04868977122003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

ENGINE COOLANT TEMPERATURE SENSOR

Note. The following procedure assumes that the cooling system thermostat is functioning properly. Test works best if performed on a totally cold engine (cold soak).

Note. For circuit identification and wiring diagram, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in appropriate SELF-DIAGNOSTICS article to ensure system is functioning properly.

Turn ignition on. Using scan tool, read Engine Coolant Temperature (ECT) sensor value. If engine coolant temperature is more than 180°F (82°C), allow engine coolant temperature to cool down to 150°F (66°C) before proceeding. If engine coolant temperature is 150°F (66°C) or less, start engine and monitor scan tool until engine coolant temperature reaches 180°F (82°C). If ECT sensor value increases smoothly, no problem is indicated at this time. Test is complete. If ECT sensor value does not increase smoothly, or never reaches 180°F (82°C) or more, check for cooling system problems and repair as necessary. If cooling system is okay, replace ECT sensor.

INTAKE AIR TEMPERATURE SENSOR

Note. When performing this test, DO NOT allow more than 5 minutes between measuring temperature of Intake Air Temperature (IAT) sensor with scan tool and measuring the air temperature inside of intake manifold with temperature probe.

Turn ignition on. Using scan tool, read and record IAT sensor value. Remove IAT sensor. (Scheme 1024), (Scheme 1025) or (Scheme 1026). Using a thermometer, read temperature inside IAT sensor opening. If IAT sensor value is within 10°F of thermometer reading, reinstall IAT sensor. IAT sensor is operating properly. Test is complete. If IAT sensor value is not within 10°F of thermometer reading, replace IAT sensor.

Scheme 1024

Scheme 1024: INTAKE AIR TEMPERATURE SENSOR

Scheme 1025

Scheme 1026

Ram Pickup (3.7L, 5.9L & 8.0L) & Ram Van

Individual component testing is not available. For leak detection pump switch testing, see the following

For Ram Pickup, see «DTC P1494: LEAK DETECTION PUMP SW OR MECHANIC»(ref-157055-S38553973142003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For Ram Van, see «DTC P1494: LEAK DETECTION PUMP SW OR MECHANIC»(ref-157603-S29641525342003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

MANIFOLD ABSOLUTE PRESSURE SENSOR

Note. For circuit identification and wiring diagram, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components. Perform appropriate verification test to ensure system is functioning properly. Perform POWERTRAIN VERIFICATION TEST VER-2 under VERIFICATION TESTS in appropriate SELF-DIAGNOSTICS article to ensure system is functioning properly.

Turn ignition off. Install vacuum "T" fitting and vacuum gauge at vacuum source on intake manifold. Start engine and allow engine to idle. If engine will not idle, maintain a constant RPM greater than idle. Note engine vacuum on vacuum gauge. Using scan tool, read Manifold Absolute Pressure (MAP) sensor vacuum. If MAP sensor vacuum is within one in. Hg of engine vacuum on vacuum gauge, MAP sensor is operating properly. Test is complete. If MAP sensor vacuum is not within one in. Hg of engine vacuum on vacuum gauge, replace MAP sensor.

PARK/NEUTRAL POSITION SWITCH

Note. Only Ram Pickup equipped with 8.0L and 47RE transmission use park/neutral position switch. All other automatic transmission applications use transmission range sensor. For other models, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

To test the switch, disconnect Park/Neutral Position (PNP) switch harness connector. Test for continuity between PNP switch center terminal and the transmission case. Continuity should exist only when transmission is in Park or Neutral. Shift the transmission into Reverse. Test continuity at PNP switch outer terminals. Continuity should exist only when the transmission is in Reverse. Continuity should not exist between PNP switch outer terminals and the case. Check gearshift linkage adjustment before replacing PNP switch that fails test.

THROTTLE POSITION SENSOR

Ensure throttle body and linkage are not binding and operate properly. Turn ignition on. Ensure throttle is fully closed and against throttle stop. Using scan tool, read Throttle Position (TP) sensor voltage with throttle fully closed. If voltage is 1.5 volts or less, go to next step. If voltage is more than 1.5 volts, replace TP sensor.
Using scan tool, monitor TP sensor voltage while slowly opening throttle from closed position to fully open position. If voltage does not change smoothly from about 0.8 volt to more than 3.5 volts, replace TP sensor. If voltage changes smoothly from about 0.8 volt to more than 3.5 volts, TP sensor is functioning properly. Test is complete.

TRANSMISSION RANGE SENSOR

Note. All automatic transmission applications use transmission range sensor except Ram Pickups equipped with 8.0L and 47RE transmission. For Ram Pickups equipped with 8.0L and 47RE transmission, see PARK/NEUTRAL POSITION SWITCH . For transmission range sensor diagnostic information, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

VEHICLE SPEED SENSOR

Individual component testing is not available. For Vehicle Speed Sensor (VSS) testing, see the following

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P0500: NO VEHICLE SPEED SIGNAL»(ref-157055-S15922686332003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see «DTC P0501: VEHICLE SPEED SIGNAL NO. 1 PERFORMANCE»(ref-157234-S42686103922003080700000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - RAM PICKUP - 4.7L & 5.7L article.
For Ram Van, see «DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL CIRCUIT»(ref-157603-S20533141382003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

A/C CLUTCH RELAY

Note. See A/C CLUTCH RELAY under MISCELLANEOUS CONTROLS.

AUTO SHUTDOWN RELAY

To test the Auto Shutdown (ASD) relay, go to step 1 . For ASD relay circuit testing, see the following

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P1388: AUTO SHUTDOWN RELAY CONTROL CIRCUIT»(ref-157055-S13292776782003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see «DTC P0685: ASD RELAY CONTROL CIRCUIT»(ref-157234-S10250484012003080800000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - RAM PICKUP - 4.7L & 5.7L article.
For Ram Van, see «DTC P1388: ASD RELAY CONTROL CIRCUIT»(ref-157603-S42039981092003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

Turn ignition off. Remove ASD relay from Power Distribution Center (PDC). see scheme 4or see scheme 5. PDC is located on left side of engine compartment.
Measure resistance between ASD relay terminals No. 85 and 86. If resistance is not 70-80 ohms, replace ASD relay. If resistance is 70-80 ohms, go to next step.
Using an ohmmeter, check for continuity between ASD relay terminals No. 30 and 87A. (Scheme 1027) If continuity exists, replace relay. If continuity does not exist, go to next step.
Using jumper wires, apply positive battery voltage to relay terminal No. 86 and ground relay terminal No. 85. Check for continuity between relay terminals No. 30 and 87. Continuity should exist. If continuity does not exist, replace ASD relay.

Scheme 1027

EVAP PURGE SOLENOID

To test EVAP purge solenoid, check Evaporative Emission System. See FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS. For evaporative purge solenoid circuit testing, see the following

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P0443: EVAP PURGE SOLENOID CIRCUIT»(ref-157055-S05778132092003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see «DTC P0443: EVAP PURGE SOLENOID CIRCUIT»(ref-157234-S27766552682003080700000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - RAM PICKUP - 4.7L & 5.7L article.
For Ram Van, see «DTC P0443: EVAP PURGE SOLENOID CIRCUIT»(ref-157603-S24669787442003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

Ram Pickup

Turn ignition off. Remove fuel pump relay from Power Distribution Center (PDC). see scheme 4 PDC is located on left side of engine compartment. Using an ohmmeter, check for continuity between fuel pump relay terminals No. 30 and 87. (Scheme 1028) If continuity exists, replace relay. If continuity does not exist, go to next step.
Measure resistance between fuel pump relay terminals No. 85 and 86. If resistance is not 50-90 ohms, replace fuel pump relay. If resistance is 50-90 ohms, go to next step.
Using jumper wires, apply positive battery voltage to relay terminal No. 86 and ground relay terminal No. 85. Check for continuity between relay terminals No. 30 and 87. Continuity should exist. If continuity does not exist, replace relay.

Scheme 1028

Ram Van

Turn ignition off. Remove fuel pump relay from fuse block. (Scheme 1029) Fuse block is located in left end of instrument panel. Using an ohmmeter, check for continuity between fuel pump relay terminals A2 and A5. To identify fuel pump relay terminals, refer to corresponding fuel pump relay cavities in fuse block. (Scheme 1029) If continuity exists, replace relay. If continuity does not exist, go to next step.
Measure resistance between fuel pump relay terminals A1 and A3. If resistance is not 50-90 ohms, replace fuel pump relay. If resistance is 50-90 ohms, go to next step.
Using jumper wires, apply positive battery voltage to relay terminal A1 and ground relay terminal A3. Check for continuity between relay terminals A2 and A5. Continuity should exist. If continuity does not exist, replace relay.

Scheme 1029

IDLE AIR CONTROL MOTOR

Note. For idle air control motor testing, see IDLE AIR CONTROL MOTOR under IDLE CONTROL SYSTEMS.

Individual component testing is not available. For leak detection pump switch testing, see the following

For Ram Pickup, see «DTC P1495: LEAK DETECTION PUMP SOLENOID CIRCUIT»(ref-157055-S08418881542003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For Ram Van, see «DTC P1495: LEAK DETECTION PUMP SOLENOID CIRCUIT»(ref-157603-S17332880782003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

FUEL SYSTEM PRESSURE RELEASE

WARNING

Fuel system is under high pressure. ALWAYS release fuel pressure before attempting to open system for testing or component replacement. DO NOT allow fuel to flow onto engine or electrical parts while testing fuel system components.

On Ram Pickup, remove fuel pump relay from Power Distribution Center (PDC). see scheme 4 PDC is located on left side of engine compartment. On Ram Van, remove fuel pump relay from fuse block. (Scheme 1029) Fuse block is located in left end of instrument panel. On all models, start and run engine until it stalls. Attempt to start engine. Continue restarting engine until it will no longer run. Turn ignition off. NOTE: One or more Diagnostic Trouble Codes (DTC) may set when fuel pump relay is removed.
Disconnect any fuel injector connector. Connect a jumper wire between either fuel injector terminal and positive battery terminal. Connect another jumper wire to other fuel injector terminal. Momentarily touch other end of jumper wire to negative battery terminal. CAUTION: DO NOT supply power to fuel injector for more than 4 seconds, or fuel injector may be damaged.
Place a shop towel under fuel line quick-connector at fuel rail. Use care when disconnecting fuel lines, as some fuel pressure may still exist in fuel lines. Disconnect fuel line quick-connector at fuel rail. Reinstall fuel pump relay in PDC. Reconnect fuel line quick-connector. Using scan tool, erase any DTCs that may have set after fuel pressure release procedure.

FUEL DELIVERY

For checking fuel pump amperage, pressure or volume, see fuel pump testing procedures under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - RAM PICKUP & RAM VAN - GASOLINE article. If fuel pump amperage, pressure or volume testing are unable to be performed, perform FUEL PUMP RELAY test under MOTORS, RELAYS & SOLENOIDS, or perform the following

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P1282: FUEL PUMP/SYSTEM RELAY CONTROL CIRCUIT»(ref-157055-S14644047002003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see «DTC P0627: FUEL PUMP RELAY CIRCUIT»(ref-157234-S08845974602003080800000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For Ram Van, see «DTC P1282: FUEL PUMP/SYSTEM RELAY CONTROL CIRCUIT»(ref-157603-S18067076932003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

Fuel Injectors

Disconnect fuel injector from wiring harness. Connect ohmmeter between fuel injector terminals. Resistance should be about 10.8-13.2 ohms at 68°F (20°C). If resistance is not as specified, replace fuel injector.

Fuel Pump Relay

Note. See FUEL PUMP RELAY under MOTORS, RELAYS & SOLENOIDS.

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P0505: IDLE AIR CONTROL MOTOR CIRCUITS»(ref-157055-S42571248482003080100000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see IAC motor related diagnostic test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-157234-S18137324412003080700000) in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For Ram Van, see «DTC P0505: IDLE AIR CONTROL MOTOR CIRCUITS»(ref-157603-S29109509142003081900000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.

Closed Crankcase Ventilation System (8.0L)

Note. Vehicle may be equipped with a Closed Crankcase Ventilation (CCV) system (8.0L) or a Positive Crankcase Ventilation (PCV) system (all others). If engine is equipped with a CCV system, it will not have a PCV valve. See EMISSION SYSTEMS & SUB-SYSTEMS . For more information on PCV system and CCV system, see EMISSION SYSTEMS & SUB-SYSTEMS in appropriate THEORY & OPERATION article.

The following procedure checks throttle body calibrations for correct idle conditions. To perform the following procedure, a Fixed Orifice Adapter (6714) measuring.185" (4.70 mm) must be used. (Scheme 1030) Procedure should only be used to diagnose the throttle body for conditions that may cause idle problems. Before performing this test, ensure Idle Air Control (IAC) motor is functioning properly. If IAC motor is not functioning properly, see Idle Air Control (IAC) motor and circuit tests, see DTC P0505: IDLE AIR CONTROL MOTOR CIRCUITS under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

Turn ignition off. Remove air duct and air cleaner resonator from top of throttle body. Disconnect tube from fixed orifice fitting at right side valve cover. Insert either end of fixed orifice adapter into disconnected tube. (Scheme 1030) Go to next step.
Connect scan tool to Data Link Connector (DLC). DLC is located below instrument panel, near steering column. Start engine and allow it to reach normal operation temperature. Turn all accessories off. Using scan tool, perform MINIMUM AIRFLOW test.
Scan tool will count down to stabilize idle RPM and display minimum airflow RPM. If idle RPM displayed is not 500-900 RPM, replace throttle body. If idle RPM displayed is 500-900 RPM, minimum airflow is okay. Test is complete.

Scheme 1030

Positive Crankcase Ventilation System (Except 8.0L)

Turn ignition off. Ensure throttle plate and linkage are not binding. Repair throttle plate and linkage as necessary before continuing. If throttle plate and linkage are okay, go to next step.
Start engine and allow it to idle. Check engine, brake booster and vacuum hoses for leaks. Ensure Positive Crankcase Ventilation (PCV) system is functioning properly. Repair vacuum leaks as necessary. If PCV system is okay and no vacuum leaks exist, go to next step. (Scheme 1031)
Turn ignition off. Disconnect vacuum hose from PCV valve. Install PCV Adapter (6714) into disconnected vacuum hose in place of PCV valve. PCV adapter is a.185" air metering orifice. (Scheme 1030) Disconnect purge hose from throttle body fitting and cap fitting. Purge hose is located on front of throttle body next to Manifold Absolute Pressure (MAP) sensor. Start engine and allow it to idle. Ensure all accessories are off. Allow engine to reach normal operating temperature. Using scan tool, actuate MIN AIRFLOW. If engine speed is 500-900 RPM, no problem is indicated at this time. Test is complete. If engine speed is not 500-900 RPM, go to next step.
Turn ignition off. Remove throttle body. While holding throttle open, spray entire throttle body bore with appropriate cleaner. Using a soft scuff pad, clean throttle body bore and throttle plate. Using compressed air, dry throttle body. Install throttle body. Ensure PCV adapter is still installed and throttle body fitting is capped. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Using scan tool, perform MINIMUM AIRFLOW test. If engine speed is not 500-900 RPM, replace throttle body. If engine speed is 500-900 RPM, no problem is indicated at this time. Test is complete.

TIMING CONTROL SYSTEMS

Ignition timing is electronically controlled by Powertrain Control Module (PCM). Base ignition timing is NOT adjustable with this system. PCM controlled ignition system consists of Engine Coolant Temperature (ECT) sensor, Crankshaft Position (CKP) sensor, Camshaft Position (CMP) sensor, ignition coil(s), Manifold Absolute Pressure (MAP) sensor and Throttle Position (TP) sensor. For ignition coil resistance test, see IGNITION COIL . For sensor component testing, see SENSORS & SWITCHES .

IGNITION COIL

Ignition coil resistance is measured at 70-80°F (21-27°C). See IGNITION COIL RESISTANCE table.

Application	Primary - Ohms	Secondary - Ohms
3.7L & 4.7L	.6-.9	6000-9000
3.9L, 5.2L & 5.9L
Diamond Coil	.97-1.18	11,300-15,300
Toyodenso Coil	.95-1.20	11,300-13,300
5.7L	(1) 0.558-0.682	—
8.0L	.53-.65	10,900-14,700
(1) Plus or minus 10 percent. .

(1)	Plus or minus 10 percent.

IGNITION COIL RESISTANCE

CLOSED CRANKCASE VENTILATION SYSTEM

Note. Two types of Closed Crankcase Ventilation (CCV) systems are used. The 8.0L uses a fixed orifice tube and all other models use a Positive Crankcase Ventilation (PCV) valve. For more information on CCV systems, see EMISSION SYSTEMS & SUB-SYSTEMS in appropriate THEORY & OPERATION article.

Fixed Orifice Tube (8.0L)

A fixed orifice tube CCV system performs same function as a conventional PCV system, but does not use a vacuum controlled PCV valve. Ensure locations of fixed orifice fitting and air inlet fitting have not been exchanged.
Fixed orifice fitting may be Gray in color and air inlet fitting may be Black in color. The fixed orifice fitting is located on right side valve cover.
Remove fixed orifice fitting from valve cover and leave tube attached. Start engine and let idle. A hissing noise should be heard from fixed orifice fitting. Also, a strong vacuum should be felt with a finger placed at fitting inlet. If vacuum is not present, remove fitting. If vacuum is now present at tube, replace fitting. Do not attempt to clean fitting. If vacuum is not present at tube, go to next step.
Check tube for kinks or obstruction. Clean tube fitting at intake manifold, if necessary. A 1/4" drill may be used (by hand) to dislodge any solid particles. Reinstall fixed orifice fitting and tube. Disconnect air inlet fitting and hose from front of valve cover.
Hold a piece of stiff paper loosely over opening in valve cover. Allow engine to idle for one minute. Paper should be drawn against rubber grommet in valve cover by vacuum in crankcase. If vacuum is not present, check tubes for restrictions or obstructions.

Positive Crankcase Ventilation Valve (Except 8.0L)

Disconnect hose from Positive Crankcase Ventilation (PCV) valve. PCV valve is located on engine oil filler tube. (Scheme 1031) Rotate PCV valve downward until locating tabs on PCV valve align with slots on filler tube. Nipple on PCV valve should now be pointing downward. Remove PCV valve. Check condition of PCV valve "O" ring and replace as necessary.
Reconnect hose to PCV valve. Start engine and allow it to idle. If valve is functioning properly, a hissing sound will be heard as air passes through valve. Place finger over PCV valve inlet. A strong vacuum should be felt at valve inlet. (Scheme 1032) If vacuum is not felt, turn ignition off and go to next step. If vacuum is felt, turn ignition off and go to step 4.
Disconnect hose from PCV valve. Remove and shake PCV valve to ensure a metallic clicking noise can be heard, indicating valve is free. If valve is not free, do not attempt to clean PCV valve. Replace valve. If PCV valve is free, check for obstructions or kinks in PCV valve hose. If hose is okay, check for plugged vacuum fitting at rear of intake manifold. Repair vacuum fitting as necessary and go to next step.
Reinstall PCV valve. Disconnect fresh air hose from air cleaner resonator on top of engine. Start engine and allow it to idle. Hold a piece of stiff paper over fresh air hose opening. (Scheme 1033) After allowing about one minute for crankcase pressure stabilization, paper should be drawn against opening. If paper is held against opening, system is functioning properly. If paper is not held against opening, check hoses/tubes and crankcase breathers for restrictions. Repair PCV system as necessary.

Scheme 1031

Scheme 1032

Scheme 1033

FUEL EVAPORATIVE SYSTEM

Note. For circuit identification and wiring diagram, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS in appropriate SELF-DIAGNOSTICS article to ensure system is functioning properly.

Checking Evaporative Emission System

Note. Engine MUST be in closed loop to perform this test.

Start engine and allow it to reach normal operating temperature. Using scan tool, select SYSTEM TESTS, then PURGE VAPORS TEST. Monitor SHORT TERM ADAPTIVE value on scan tool and press "3" to flow. SHORT TERM ADAPTIVE value should change. If value changes, no problem is indicated at this time. Test is complete. If short term adaptive value does not change, go to next step.
Using scan tool, review FREEZE FRAME DATA. Attempt to duplicate condition that caused DTC to set. Visually inspect related connectors and wiring harness for damage. Inspect for cracked, pinched or broken hoses from purge solenoid to EVAP canister and to fuel tank. Check for any related technical service bulletins that may apply. Repair hoses or wiring harness as necessary. If no problems are present, go to next step.
Turn ignition on. Using scan tool, actuate EVAP PURGE SOLENOID. Wiggle EVAP purge solenoid wiring harness and listen for EVAP purge solenoid to quit actuating. Using scan tool, read DTCs. If GOOD TRIP counter is displayed and displayed count changes to "0", or EVAP purge solenoid quits actuating, repair wiring where wiggling caused EVAP purge solenoid to quit actuating. If EVAP purge solenoid does not stop actuating and GOOD TRIP counter is not displayed or displayed count does not change to "0", go to next step.
Turn ignition off. Remove EVAP purge solenoid. Inspect line from rollover valve to solenoid. Rollover valves are located on top of fuel tank. If any fuel is in rollover valve line, replace rollover valve. Rollover valves are located on top of fuel tank. On Ram Van, rollover valves mounted permanently to top of fuel tank are not serviceable. On Ram Pickup, rollover valve located on top of fuel pump module may be serviced separately. If fuel tank mounted rollover valve is defective, fuel tank must be replaced. See FUEL TANK under FUEL SYSTEMS in appropriate REMOVAL & INSTALLATION article. Replace rollover valve or fuel tank as necessary. If rollover valve is okay and no fuel is in rollover valve hose, go to next step.
Remove EVAP purge solenoid. Tap EVAP purge solenoid ports against a clean, solid surface. If foreign material falls out of ports, replace EVAP purge solenoid and clean or replace vacuum and purge lines and EVAP canister as necessary. If no foreign material falls out of ports, no problem is indicated at this time. Test is complete.

DRIVEABILITY PROBLEMS

Note. Diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRBIII®) scan tool. A generic scan tool may not be capable of performing all necessary test functions.

START & STALL CONDITION

Note. For circuit identification and wiring diagrams, see WIRING DIAGRAMS . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS in appropriate SELF-DIAGNOSTICS article to ensure system is functioning properly.

For testing procedures (Scheme 1034)and (Scheme 1035).

Scheme 1034

Scheme 1034: START & STALL CONDITION

Scheme 1035

MISCELLANEOUS CONTROLS

Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.

Individual component testing is not available, For A/C clutch relay circuit testing, see the following

For 3.7L, 5.9L and 8.0L Ram Pickup, see «DTC P0645: A/C CLUTCH RELAY CIRCUIT»(ref-157055-S29577957262003080400000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM PICKUP 3.7L, 5.9L (GASOLINE) & 8.0L article.
For 4.7L and 5.7L Ram Pickup, see IAC motor related diagnostic test. See «DTC P0645: A/C CLUTCH RELAY CIRCUIT»(ref-157234-S16725996272003080700000) in SELF-DIAGNOSTICS - RAM PICKUP 4.7L & 5.7L article.
For Ram Van, see «DTC P0645: A/C CLUTCH RELAY CIRCUIT»(ref-157603-S14999547982003082000000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - RAM VAN article.