Engine Controls - Basic Diagnostic Procedures - Gasoline: Other Dodge Cab & Chassis R3500

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).

Programming Powertrain Control Module

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.

Compression

Ensure battery is fully charged and starter motor is in good operating condition. Clean spark plug recesses with compressed air. Remove all spark plugs. On Ram Pickup, remove fuel pump relay from Power Distribution Center. (PDC) (Scheme 121)or (Scheme 122). On Ram Van/Ram Wagon, remove fuel pump relay from fuse block. Fuse block is located behind left kick panel. On all models, install compression gauge. Hold throttle in wide open throttle position. Using a remote starter switch, rotate engine 3 revolutions. Record compression pressure from third revolution. Continue test for remaining cylinders. See COMPRESSION SPECIFICATIONS table for correct engine compression pressures.

COMPRESSION SPECIFICATIONS

Scheme 121

Scheme 122

Vacuum

Note. Vacuum readings can vary according to altitude.

Turn ignition off. Install vacuum "T" fitting and vacuum gauge at vacuum source on intake manifold. Start engine and allow it to idle. While monitoring vacuum gauge reading, quickly open (snap) throttle to full open and back to closed position several times. Vacuum gauge reading should change from about 13-22 in. Hg. If vacuum reading is within specification, test is complete. If vacuum reading is not within specification, check for engine mechanical condition. See appropriate article in ENGINES.

FUEL SYSTEM PRESSURE RELEASE

1. On Ram Pickup, remove fuel pump relay from Power Distribution Center (PDC). (Scheme 121) PDC is located in right side of engine compartment, next to battery. On Ram Van/Ram Wagon, remove fuel pump relay from fuse block. Fuse block is located behind left kick panel. (Scheme 123) 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.
2. 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.
3. 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.

Scheme 123

All Models

1. Disconnect negative battery cable. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-99022-S36246382032001061300000) . Install fuel pressure gauge with hose on fuel pressure test port.
2. Start engine, allow to idle and reach operating temperature. Fuel pressure should be 44.2-54.2 psi (3.1-3.8 kg/cm 2 ). If no fuel pressure exists and engine will not start, fuel pump relay and control circuit may be defective. See «FUEL PUMP RELAY»(ref-99022-S33864200442001061300000) .
3. If engine runs but fuel pressure is less than specified, check for kinked or damaged fuel line between fuel pump module and fuel rail. Repair fuel line as necessary and retest. If fuel line is okay, perform «FUEL PUMP AMPERAGE TEST»(ref-99022-S20696965942001061300000) , «FUEL PUMP VOLUME TEST»(ref-99022-S35176149742001061300000) and «FUEL PRESSURE LEAKDOWN TEST»(ref-99022-S31780161892001061300000) . If specifications were not met for FUEL PUMP AMPERAGE TEST, FUEL PUMP VOLUME TEST or FUEL PRESSURE LEAKDOWN TEST, replace fuel pump module. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If fuel pressure exceeds specification, fuel pump is okay, but fuel pressure regulator is defective. Replace fuel pressure regulator. Fuel pressure regulator is incorporated with the fuel filter. Fuel filter/fuel pressure regulator is located on top of fuel tank, in fuel pump module. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.

Fuel Pump Relay

For fuel pump relay test, see FUEL PUMP RELAY under MOTORS, RELAYS & SOLENOIDS in appropriate SYSTEM & COMPONENT TESTING article. For fuel pump relay circuit testing, see DTC P1282: FUEL PUMP RELAY CONTROL CIRCUIT under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

CAMSHAFT POSITION SENSOR

Note. For Camshaft Position (CMP) sensor circuit testing, see DTC P0340: NO CAM SIGNAL AT PCM under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

CRANKSHAFT POSITION SENSOR

Note. For Crankshaft Position (CKP) sensor circuit testing, see DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM under DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.

IGNITION COIL

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

IGNITION COIL RESISTANCE

SPARK PLUG WIRES

SPARK PLUG WIRE RESISTANCE

ENGINE CRANKS BUT DOES NOT START

Note. For circuit identification and wiring diagrams, see WIRING DIAGRAMS article. After each repair procedure has been completed, reconnect all components. Perform TEST VER-5: OBD-II MONITOR VERIFICATION under VERIFICATION TESTS to ensure system is functioning properly.

ENGINE WILL NOT CRANK

Note. For circuit identification and wiring diagrams, see WIRING DIAGRAMS article. For starter relay wiring diagram, see appropriate STARTERS article in STARTING & CHARGING SYSTEMS. After each repair procedure has been completed, reconnect all components. Perform TEST VER-1: POWERTRAIN VERIFICATION under VERIFICATION TESTS to ensure system is functioning properly.

NO RESPONSE FROM PCM WITH A NO-START CONDITION

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

DRIVEABILITY PROBLEMS

Note. Diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRB-III(R)) 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 article. After each repair procedure has been completed, reconnect all components. Perform TEST VER-1: POWERTRAIN VERIFICATION under VERIFICATION TESTS to ensure system is functioning properly.

SUMMARY

If no faults were found while performing basic diagnostic procedures, proceed to appropriate SELF-DIAGNOSTICS article. If no Diagnostic Trouble Codes (DTC) are found in self-diagnostics, proceed to appropriate TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.) or intermittent diagnostic procedures.