Engine Controls - Basic Diagnostic Procedures - Gasoline: Diagnosis Dodge Pickup R1500

VISUAL INSPECTION

Most driveability problems in the engine control system result from faulty wiring, poor electrical connections or leaking air and vacuum hose connections. To avoid unnecessary component testing, perform a visual inspection before beginning self-diagnostic tests.

Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not cracked, pinched or cut. See VACUUM DIAGRAMS - TRUCKS article. Inspect air induction system for possible vacuum leaks.

MECHANICAL INSPECTION

Check engine mechanical condition with a compression gauge, vacuum gauge or scan tool. See scan tool manual for specific instructions.

Testing

1. The following checks must be performed before continuing with this test: Ensure battery is fully charged and in good condition. If battery charge is low, charge battery and crank engine for 15 seconds, 3 consecutive times. This will allow any Diagnostic Trouble Codes (DTC) that may have been erased due to low battery charge to set in memory. Ensure Powertrain Control Module (PCM) power and ground circuits are okay. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article. Ensure PCM communicates with scan tool and no Diagnostic Trouble Codes (DTC) are present. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article. Ensure CCD bus is functional. Using scan tool, attempt to communicate with instrument cluster and Central Timer Module (CTM). If scan tool does not communicate with instrument cluster or CTM, diagnose communication failure. See COMMUNICATIONS under SYSTEM TESTS in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. If no DTCs are present, use scan tool and select CLEAR PCM (BATT DISCONNECT). Crank engine over several times. Using scan tool, check for DTCs. If any DTCs are present, perform appropriate diagnostic test. See appropriate SELF-DIAGNOSTICS article. If no DTCs are present, go to next step.
2. Turn ignition off. On Ram Pickup, check for blown fuses in Power Distribution Center (PDC). PDC is located on left side of engine compartment. On Ram Van, check for blown fuses in junction block. Junction block is located behind left kick panel. On all models, replace blown fuses and check related circuits for short to ground. If fuses are okay, go to next step.
3. Turn ignition on. Using scan tool under DTCs & RELATED FUNCTIONS menu, monitor SECONDARY INDICATORS while cranking engine. If no SECONDARY INDICATORS exist, go to next step. If any SECONDARY INDICATORS exist, perform appropriate symptom test related to indicator. See appropriate REMOVAL & INSTALLATION article.
4. Ensure ignition is on. Using scan tool in INPUTS/OUTPUTS mode, read CURRENT SYNC STATE while cranking engine. If scan tool does not display OUT OF SYNC, go to next step. If scan tool displays OUT OF SYNC, check CKP sensor signal circuit for short to CMP sensor signal circuit. See «WIRING DIAGRAMS»(ref-157772-S01608353052003082600000). Repair wiring as necessary. If wiring is okay, check for incorrect valve timing or for CMP sensor drive problem. Repair valve timing or CMP sensor drive as necessary. See appropriate article in ENGINES.
5. Ensure ignition is off. On Ram Pickup, remove ASD relay from Power Distribution Center (PDC). see scheme 1 PDC is located in right side of engine compartment, next to battery. On Ram Van, remove fuel pump relay from fuse block. see scheme 2 Fuse block is located in left end of instrument panel. see scheme 10 On all models, disconnect PCM connectors. (Scheme 995)or (Scheme 996). Ensure ASD relay or fuel pump relay is supplied battery voltage. Measure resistance of circuits between ASD relay or fuel pump relay output terminal and PCM, ignition coil(s), and fuel injectors. See «WIRING DIAGRAMS»(ref-157772-S01608353052003082600000). If every resistance is less than 5 ohms, go to next step. If any resistance is 5 ohms or more, repair affected circuit.
6. Check the following conditions and/or mechanical components: Ensure engine valve timing is within specification. Ensure engine compression is within specification. See «COMPRESSION SPECIFICATIONS»(ref-157772-S30912714632003082600000) table. Ensure engine exhaust system is free of restrictions and/or leaks. Ensure fuel is free of contamination. Ensure fuel injectors are not plugged or restricted, and injector driver circuit wires are connected to proper fuel injectors. Repair as necessary. If no faults are found, go to next step.
7. Ensure fuel tank is not empty. Check fuel delivery. See «FUEL PUMP PRESSURE TEST»(ref-157772-S08775417632003082600000) under FUEL SYSTEMS. If problem is found, repair as necessary. If no problem is found, check for fuel contamination. Ensure fuel meets manufacturer's requirements. Replace fuel as necessary.

Scheme 995

Scheme 996

Note. Ensure ignition was on and DRBIII(R) scan tool in proper working order prior to attempting communication with PCM.

Note. On Ram Pickup, the PCM connector terminals are identified using numbers (C1, terminal No. 17). On Ram Van, PCM connector terminals are identified using an alpha character and numbers (C1, terminal No. A17). Connector C1 uses "A" prefix, connector C2 uses "B" prefix and connector C3 uses "C" prefix. In the following test, only the number is called out.

Scheme 997

1. Turn ignition off. Disconnect PCM connectors. (Scheme 995)or (Scheme 996). Inspect connectors for damaged pins, corrosion and loose terminals. Repair connectors as necessary. Using a 12-volt test light connected to ground, probe PCM harness connector C1 terminal No. 22 (Red/White wire on Ram Pickup, or Dark Green/Black wire on Ram Van). (Scheme 997) If test light illuminates brightly, go to next step. If test light does not illuminate brightly, check for open in Red/White or Dark Green/Black wire between Power Distribution Center (PDC) and PCM. If wiring is okay, check for blown fuse No. 3 (Ram Pickup) or No. 17/18 (Ram Van) in PDC. PDC is located on left side of engine compartment. see scheme 1or (Scheme 996).
2. Turn ignition on. Using a 12-volt test light connected to ground, probe PCM harness connector C1 terminal No. 2 (Light Green/Black wire). (Scheme 997) If test light illuminates brightly, power circuits are okay. Go to next step. If test light does not illuminate brightly, repair open in Light Green/Black wire between PCM and junction block (Ram Pickup) or fuse block (Ram Van). If wiring is okay, check for blown junction block fuse No. 9 (Ram Pickup), or blown fuse block fuse No. 6 (Ram Van). Junction block and fuse block are located behind left kick panel.
3. Turn ignition off. Using 12-volt test light connected to positive battery voltage, probe PCM harness connector C1 terminals No. 31 and 32 (Black/Tan wires). (Scheme 997) If test light illuminates brightly at both terminals, go to next step. If test light does not illuminate brightly at one or both terminals, repair open in appropriate Black/Tan wire between PCM and ground point. On Ram Pickup, ground point is located on front of engine. On Ram Van, ground point is located at rear of left cylinder head.
4. On all models, turn the ignition off. Disconnect the TP sensor harness connector. Turn ignition on. Measure the voltage at TP sensor harness connector terminal No. 1 (Orange wire). Is the voltage between 4.5 and 5.2 volts? If yes, go to next step. If no, go to step 6.
5. Turn the ignition off. Disconnect the MAP Sensor harness connector. Connect TP sensor harness connector. Turn ignition on. Measure the voltage at MAP harness connector terminal No. 3 (Orange wire). Is the voltage between 4.5 and 5.2 volts? If yes, and scan tool communication is available with a PCM on a similar vehicle, go to step 9. If no, replace the TP sensor.
6. Turn the ignition off. Disconnect the TP sensor harness connector. Turn ignition on. Measure the voltage (backprobe) at PCM harness connector C1 terminal No. 17 (Orange wire). Disconnect all the sensors that use a 5-Volt Supply circuit. Did the voltage return to 4.5 to 5.2 volts when disconnecting any of the sensors? If yes, replace the sensor that is pulling down the 5-Volt supply. If no, go to next step.
7. Turn the ignition off. Disconnect PCM harness connector. Disconnect all the sensors that share the Primary 5-Volt Supply circuit (CKP sensor, CMP sensor, MAP sensor and TP sensor). See «WIRING DIAGRAMS»(ref-157772-S01608353052003082600000). Measure the resistance between ground and PCM harness connector C1 terminal No. 17 (Orange wire). Is the resistance below 100 ohms? If yes, repair the short to ground in the Primary 5-Volt Supply circuit. If no, go to next step.
8. Turn the ignition off. Disconnect the PCM harness connector C2. Disconnect all sensors that receive Auxiliary 5-Volt Supply (Transmission solenoid assembly on all models and A/C pressure transducer on Ram Pickup, if equipped). See WIRING DIAGRAMS article. Measure the resistance between ground and PCM harness connector C2 terminal No. 31 (Violet/White wire). Is the resistance below 100 ohms? If yes, repair the short to ground in the Auxiliary 5-Volt Supply circuit. Perform «POWERTRAIN VERIFICATION TEST VER-1»(ref-157772-S10901420662003082600000) under VERIFICATION TESTS. If no, go to next step.
9. If there is no possible causes remaining, replace and program the PCM.

FUEL PRESSURE LEAKDOWN TEST

Note. Perform FUEL PUMP PRESSURE TEST before performing FUEL PRESSURE LEAKDOWN TEST. Perform FUEL PUMP VOLUME TEST in conjunction with fuel pump pressure test. After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS to ensure system is functioning properly.

1. Release fuel system pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-157772-S14853159042003082600000). Remove air cleaner housing (if necessary) to access quick-connect fuel fittings. Disconnect fuel supply line quick-connect fittings at fuel rail. Connect Fuel Line Pressure Test Adapter (6539 ) for 5/16" fuel lines, or Fuel Line Pressure Test Adapter (6631 ) for 3/8" fuel lines, and test port "T" between disconnected fuel supply line and fuel rail.
2. Connect 0-60 psi fuel pressure test gauge to test port "T" on appropriate Fuel Line Pressure Test Adapter. (Scheme 998) Start engine and bring to normal operating temperature. Observe fuel pressure test gauge. Fuel system pressure should be 44.2-54.2 psi (305-374 kPa). Shut engine off. Fuel system pressure should not fall to less than 30 psi (207 kPa) for 5 minutes. Go to next step.
3. If fuel system pressure falls to less than 30 psi (207 kPa), check fuel injector, check valve inside fuel pump module or fuel tube/line for leaks. To diagnose components and pinpoint fuel system leaks, perform the following tests: Fuel Injector Or Fuel Rail Leakage Start engine and operate at idle for 2 minutes. Shut off engine. Clamp off rubber hose portion of Fuel Line Pressure Test Adapter between fuel rail and test port "T" on Fuel Line Pressure Test Adapter. If fuel system pressure does not fall to less than 30 psi (207 kPa) for 5 minutes, fuel injector or fuel rail is leaking. Repair as necessary. Fuel Pump Check Valve, Filter/Regulator Check Valve Or Fuel Tube/Line Leakage Start engine and operate at idle for 2 minutes. Shut off engine. Clamp off rubber hose portion of Fuel Line Pressure Test Adapter between vehicle fuel line and test port "T" on Fuel Line Pressure Test Adapter. If fuel system pressure does not fall to less than 30 psi (207 kPa) for 5 minutes, fuel rail and fuel injectors are not leaking. Check fuel lines and tubes for leakage. If fuel lines and tubes are okay, check electric fuel pump or filter/regulator check valves for leakage. A quick loss of fuel system pressure usually indicates defective check valve in the filter/regulator. A slow loss of pressure usually indicates a defective check valve in the electric fuel pump. Repair as necessary.

Scheme 998

FUEL PUMP AMPERAGE TEST

Note. Perform FUEL PUMP VOLUME TEST , FUEL PUMP PRESSURE TEST and FUEL PRESSURE LEAKDOWN TEST before performing FUEL PUMP AMPERAGE TEST. After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS to ensure system is functioning properly.

Scheme 999

1. Ensure fuel tank temperature is more than 50°F (10°C). Connect Low Current Shunt (LCS) adapter into DRBIII(R) scan tool SET 1 connector. (Scheme 999) Connect DRBIII(R) scan tool to Data Link Connector (DLC). see scheme 3or see scheme 4. Connect test lead cables into 10-amp (10A +) and common (-) connectors on LCS. Access MAIN MENU on scan tool. Press DVOM button.
2. Use left/right arrow keys to highlight CHANNEL 1 function on scan tool. Press ENTER 3 times. Use up/down arrow keys to high light RANGE on scan tool. Press ENTER to change from 2-amp scale to 10-amp scale. Depending on model of vehicle, 3 different types of fuel pump relays are used. Use the following procedure for appropriate model and relay: If equipped with type-1 relay, attach test leads from LCS adapter into PDC relay cavities No. 30 and 87. For location of these cavities, refer to numbers stamped to bottom of relay. (Scheme 1000) If equipped with type-2 relay, attach test leads from LCS adapter into PDC relay cavities No. 30 and 87. For location of these cavities, refer to numbers stamped to bottom of relay. (Scheme 1001) If equipped with type-3 relay, attach test leads from LCS adapter into PDC relay cavities No. 3 and 5. For location of these cavities, refer to numbers stamped to bottom of relay. (Scheme 1002) Fuel pump will be operated when LCS adapter leads are connected to relay cavities. Read fuel pump amperage from DRBIII(R) scan tool screen. Amperage should be less than 10 amps. If amperage is 10 amps or more, replace fuel pump module assembly. If amperage is less than 10 amps and FUEL PUMP PRESSURE, FUEL PUMP VOLUME and FUEL PRESSURE LEAK DOWN test readings are okay, fuel pump module is okay.

Scheme 1000

Scheme 1001

Scheme 1002

FUEL PUMP PRESSURE TEST

Note. After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS to ensure system is functioning properly.

1. Disconnect negative battery cable. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-157772-S14853159042003082600000). Install fuel pressure gauge with hose on fuel pressure test port. (Scheme 1003)
2. Start engine, allow to idle and reach operating temperature. Fuel pressure should be 44.2-54.2 psi (305-374 kPa). If no fuel pressure exists and engine will not start, fuel pump relay and control circuit may be defective. See «FUEL PUMP CONTROL CIRCUIT»(ref-157772-S21213150162003082600000).
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-157772-S01806633532003082600000), «FUEL PUMP VOLUME TEST»(ref-157772-S25349814182003082600000) and «FUEL PRESSURE LEAKDOWN TEST»(ref-157772-S38197478032003082600000). 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 & 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 & INSTALLATION article.

Scheme 1003

FUEL PUMP VOLUME TEST

Note. Perform FUEL PUMP PRESSURE TEST before performing FUEL PUMP VOLUME TEST. Perform FUEL PRESSURE LEAKDOWN TEST in conjunction with FUEL PUMP VOLUME TEST. See FUEL PRESSURE LEAKDOWN TEST . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS to ensure system is functioning properly.

1. Release fuel system pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-157772-S14853159042003082600000) . Remove air cleaner housing (if necessary) to access quick-connect fuel fittings. Disconnect fuel supply line quick-connect fittings at fuel rail. Connect Fuel Line Pressure Test Adapter (6539 ) for 5/16" fuel lines, or Fuel Line Pressure Test Adapter (6631 ) for 3/8" fuel lines, to the disconnected fuel supply line.
2. Insert other end of fuel line pressure test adapter into a graduated container. Remove fuel filler cap. Using DRBIII(R) scan tool, actuate fuel pump relay. This should activate fuel pump and pressurize system. Fuel pump should deliver at least .5 pt. (.25 L) of fuel in 7 seconds. If volume is lower than specification, but fuel pump can be heard through fuel filler, check for a kinked or damaged fuel supply line between fuel rail and fuel pump module. Go to next step.
3. If fuel supply line is not kinked or damaged and fuel pressure is okay, but capacity is low, replace fuel filter/fuel pressure regulator. Fuel pressure regulator can be replaced separately on some models. If both fuel volume and pressure are low, replace fuel pump module assembly. See FUEL PUMP MODULE under FUEL SYSTEMS in appropriate REMOVAL & INSTALLATION article.

POWERTRAIN VERIFICATION TEST VER-1

Note. If Powertrain Control Module (PCM) is replaced, the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into the PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Controller Anti-Lock Brake (CAB) module and Air Bag Control Module (ACM). To program PCM and clear DTCs from CAB and ACM modules. See PROGRAMMING in appropriate REMOVAL & INSTALLATION article.

Inspect vehicle to ensure all components related to repair are properly connected. Reassemble and reconnect components as necessary. Inspect engine oil for fuel contamination. Change engine oil and filter as necessary. Attempt to start engine. If engine starts and stays running, test is complete. If engine does not start, or starts and stalls, check for related technical service bulletins and return to NO-START DIAGNOSIS for additional testing.

POWERTRAIN VERIFICATION TEST VER-2

For testing procedures (Scheme 1004)

Scheme 1004

POWERTRAIN VERIFICATION TEST VER-5

For testing procedures (Scheme 1005)

Scheme 1005