939003573 - D012 ENGINE IDLING TOO LOW

The customer complains of: Engine idle speed too low
Results of the tests
1AMBIENT PARAMETERS CHECKAll OKProblems encounteredOperation
Select the following control unit at the diagnostic equipment: EDC16C39 Diesel electronic injection control unit.Check the value of the following parameters:. Battery voltage    See Test 5530BB BATTERY VOLTAGE CHECK. Accelerator pedal. Accelerator position 1 AD/C. Accelerator position 2 AD/C    See Test 1068AC ACCELERATOR PEDAL CHECKS. Engine rpm    See Test 1060GI ENGINE SPEED CHECK. Objective Diesel pressure. Measured Diesel pressure    See Test 1060GH DIESEL FUEL PRESSURE CHECKMove on to Step 2
2CONFIGURATION TESTSAll OKProblems encounteredOperation
Select the following control unit at the diagnostic equipment: EDC16C39 Diesel electronic injection control unit.Check in the Configurations section whether the replacement of any of the following components was not followed by the subsequent configuration:. Flow meter. Fuel pressure sensor. Injector. Differential pressure sensor on the catalytic converter. Lambda sensor. Main catalytic converter with filter. Pre-catalyzerIn this case, carry out the configuration checking that the outcome is positiveMove on to Step 4The outcome of the configuration is not positiveMove on to Step 3
3CONFIGURATION REPETITIONAll OKProblems encounteredOperation
Repeat the configuration, check that the outcome is positive this timeMove on to Step 4The outcome of the configuration is not positiveReplace the engine management control unit    Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R
4ELECTRICAL EQUIPMENT CHECKAll OKProblems encounteredOperation
Check that fuse F1 has not blown (it is the last one at the bottom of the vertical row).
The check on the following system is only necessary if the outside temperature is below 0 °C.
Move on to Step 5Fuse F1 has blownRestore the connections or, if necessary, replace the junction unit in the engine compartment    Op. 5505A13 ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R.
5CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
Carry out the active diagnosis for the E.G.R. solenoid valveMove on to Step 6Solenoid valve not workingRestore the wiring continuity    See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT Replace the solenoid valve if necessary    Op. 1080C24 E.G.R. SYSTEM SOLENOID - R + R
6FUEL FILTER CHECKAll OKProblems encounteredOperation
Check fuel filter operationMove on to Step 7Water, petrol, paraffin or dirt found to be presentClean the tank and pipes and replace the diesel filter cartridgeOp. 1044B20
7VALVE CLEARANCE CHECKAll OKProblems encounteredOperation
Check that the tappet clearance is correct    Op. 1036H10 VALVE TAPPETS - CHECK AND ADJUST CLEARANCE, IF NECESSARY Move on to Step 8Valve clearance not correctAdjust the tappets
8CYLINDER COMPRESSION CHECKAll OKProblems encounteredOperation
Carry out the cylinder compression check    Op. 0520G15 COMPRESSION TEST - CHECK WITH EXAMINER WITH SPARK PLUGS/INJECTORS REMOVEDMove on to Step 10Cylinder compression insufficientMove on to Step 9
9CHECK THE CAUSE OF THE INSUFFICIENT COMPRESSIONAll OKProblems encounteredOperation
Carry out    Op. 1016C10 SINGLE CYLINDER HEAD - R.R. AND REPLACE GASKET to check the valve seal and check the condition of the cylinders/piston ringsMove on to Step 10Valve seal insufficientOverhaul the cylinder head    Op. 1016E10 SINGLE CYLINDER HEAD, REMOVED - OVERHAUL
10CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsReplace the engine management control unit    Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R