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

VISUAL INSPECTION

1. Check Water-In-Fuel (WIF) sensor electrical connector for corrosion, damaged terminals or wiring and tight fit on engine wiring harness. WIF sensor is located in bottom of fuel filter/water separator. (Scheme 1036)
2. Ensure engine is off. Place drain pan below drain tube at fuel filter/water separator. (Scheme 1036) With engine not running, rotate handle on drain valve upward, to OPEN (DRAIN) position. Drain valve is located near top of fuel filter/water separator. Drain water from fuel filter/water separator.
3. If no water exists and a clean flow of diesel fuel exists, rotate handle on drain valve downward, to CLOSE position. Go to next step. If water exists, allow water to drain until clean flow of diesel fuel exists. Rotate handle on drain valve downward, to CLOSE position. Go to next step.
4. Verify fuel filter/water separator has been serviced according to proper service schedule. See «SERVICE & ADJUSTMENT SPECIFICATIONS - RAM PICKUP - DIESEL»(ref-152170) article. NOTE: The Yellow disc in Filter Minder (FM) may reach Red zone if air intake is restricted or air filter has become wet during heavy rain or snow. If air filter has become wet, allow air filter to dry during normal engine operation and reset FM by pressing rubber button on top of FM.
5. Check color of Filter Minder (FM). FM is located on top cover on air filter housing, just above air filter. DO NOT remove air filter from air filter housing for inspection. If Yellow disc in FM has reached Red zone, remove and inspect air filter. (Scheme 1037) If air filter is dirty, replace air filter and reset FM by pressing rubber button on top of FM.
6. Ensure intercooler inlet and outlet duct clamps are tight and front of intercooler is not restricted with dirt. (Scheme 1038)
7. Ensure connections on both batteries are tight and not corroded. Ensure the three 32-pin connectors are fully engaged on Powertrain Control Module (PCM). PCM is located on firewall at passenger's side rear corner of engine compartment. see scheme 2
8. Check for loose, defective or corroded connections at Intake Air Temperature (IAT) sensor. (Scheme 1039)
9. Ensure electrical connections on intake manifold air heater relays and intake manifold air heater are tight and not corroded. Intake manifold air heater relays are mounted on inner wheelwell, below driver's side battery. (Scheme 1040) Intake manifold air heater is located between air inlet housing and intake manifold cover. (Scheme 1041) NOTE: Restricted low-pressure fuel lines from fuel tank to fuel transfer pump, fuel heater and fuel filter/water separator may cause starting problems and prevent engine from accelerating. Restricted high-pressure fuel lines from fuel injection pump to fuel injector may cause starting problems, poor engine performance and excessive Black smoke.
10. Check all fuel supply and returns lines for damage, kinking or leakage. Check throttle linkage for binding. Check for a stretched or disconnected throttle return spring.
11. Ensure all ground connections are tight and free of corrosion. See «WIRING DIAGRAMS»(ref-157961-S23937195342003090400000). Ensure accessory drive belt is not damaged or slipping. Check for loose or defective electrical connection on Camshaft Position (CMP) sensor. see scheme 1
12. On A/T models, ensure all electrical connectors are clean and properly connected to electrical plugs on transmission case. On all models, check for loose or defective electrical connections on starter and starter solenoid.

Scheme 1036

Scheme 1037

Scheme 1038

Scheme 1039

Scheme 1040

Scheme 1041

Compression Test

Ensure batteries are completely charged and the engine starter motor is in good operating condition. Otherwise, the indicated compression pressures may not be valid for diagnostic purposes.

1. Disconnect the fuel inlet line to the fuel transfer pump. Plug the fuel line from the fuel tank.
2. Start the engine and idle until the engine stalls (runs out of fuel).
3. Disconnect all 3 injector wire harness connectors at the rocker housing.
4. Remove the breather cover and cylinder head cover.
5. Remove the high pressure fuel line between the cylinder head and fuel rail for the cylinder to be tested.
6. Remove the exhaust rocker lever.
7. Use Fuel Injector Tool (9010) to remove the injector and copper sealing washer. (Scheme 1042)
8. Install the exhaust rocker lever and torque to 32 ft. lbs. (43 N.m). Cover the remaining rocker levers with clean shop towels to prevent any oil splatter under the hood.
9. Place a rag over the compression test tool fitting. Crank the engine for 2-3 seconds to purge any fuel that may have drained into the cylinder when the injector was removed.
10. Connect the compression test gauge.
11. Crank the engine for 5 seconds and record the pressure reading. Repeat this step 3 times and calculate the average of the 3 readings.
12. Combustion pressure leakage can be checked if cylinder pressure is below the specification. See «COMPRESSION SPECIFICATIONS»(ref-157961-S40889450502003090400000) table. Perform the leakage test procedure on each cylinder. See «COMBUSTION PRESSURE LEAK TEST»(ref-157961-S32980197492003090400000).
13. Upon completion of the test check an erase any engine related fault codes.

COMPRESSION SPECIFICATIONS

Scheme 1042

Combustion Pressure Leak Test

The combustion pressure leakage test provides an accurate means for determining engine condition. The combustion pressure leakage testing will detect

1. Exhaust and intake valve leaks (improper seating).
2. Leaks between adjacent cylinders or into water jacket.
3. Any causes for combustion/compression pressure loss.

1. Start and operate the engine until it attains normal operating temperature.
2. Remove the breather cover and cylinder head cover.
3. Disconnect all 3 injector wire harness connectors at the rocker housing.
4. Bring the cylinder to be tested to TDC.
5. Remove the high pressure fuel line between the cylinder head and the fuel rail for the cylinder to be tested.
6. Install Pressure Cap Tool (9011) onto the rail. (Scheme 1043)
7. Remove the high pressure connector nut and high pressure connector with Fuel Injector Tube Connector (9015). (Scheme 1044)
8. Remove the exhaust and intake rocker lever.
9. Use Fuel Injector Tool (9010) to remove the injector and copper sealing washer. (Scheme 1042)
10. Install Compression Test Tool (9007) into the injector bore. (Scheme 1045)
11. Connect the leakage tester and perform the leakage test procedure on each cylinder.
12. Upon completion of the test check and erase any engine related fault codes.

Scheme 1043

Scheme 1044

Scheme 1045

Diagnosing Leaks

Note. A leaking fuel injector may cause a rough idle, Black smoke, poor engine performance, poor fuel economy and fuel knock. Since a leaking high-pressure fuel line may cause the same symptoms, check for leaking high-pressure fuel line before checking fuel injector.

To check for a leaking high-pressure fuel line, start engine and allow engine to idle. Inspect high-pressure fuel lines and connections for signs of fuel leakage by placing cardboard over high-pressure fuel line and connection. (Scheme 1046) Note if leak is being detected by fuel being sprayed onto the cardboard. If leak exists, repair leak by tightening high-pressure fuel line nut or replacing high-pressure fuel line as necessary. Torque to 22 ft. lbs. (30 N.m).

Scheme 1046