Service News
Copyright By Fiat Group Automobiles S.p.A. - Printed 08/02/2013


Alfa MiTo


Version: 1.4 TurboJet 120 HP LPG Euro 4
10
03.13
1043 0 000 AA LPG INJECTION SYSTEM - EURO 4
Engine misfiring while driving - Network Information


FAULT COMPLAINED OF

The Customer complains of one or more of the following faults:

  • Misfiring, power levelling, jerking / loss of power while driving.

TECHNICAL CAUSE

Irregular operation of the LPG system.

OPERATIONS IN NETWORK

Once the customer's claimed fault is confirmed, before replacing any component of the system, use the diagnosis equipment to perform the following preliminary checks, where required, with reference to the Service Manual.

Before starting any diagnosis activity, make sure that the list of components does not require any Tutorship action for the dedicated areas, otherwise open directly a Tutorship ticket.

OPERATION CYCLE

The procedures below specifically refer to LPG Euro 4 versions with Turbo engines; for Euro 5 versions, refer to SN 10.02.13.

If one or more component must be replaced, open a Te.Se.O. ticket.

 

Step

  

Check

  

Re. Op.

  

Result

  

Operation
 

1

  

General conditions of the engine compartment

(wiring and pipe integrity)

  

#

  

OK

  

No fault

  

Next step
 

KO

  

Non-compliant components

  

Restore the correct conditions of the components

- -

Next step
 

2

  

Engine oil and fluid level

  

0010Txx

  

OK

  

No fault

  

Next step
 

KO

  

Levels not correct

  

Restore the correct conditions of the levels

- -

Next step
 

3

  

Fuel level (LPG) signalled by the level gauge sensor on the tank multivalve

  

1043A63

  

OK

  

Consistency with the value on the LED indicator (integrated in the shifting key) placed on the dashboard inside the car

  

Next step
 

KO

  

Non-consistent level indication

  

Restore the rated operating conditions

- -

Next step
 

4

  

Software update of the Engine Control Unit (ECU) and of the LPG system control unit (SDU)

  

Diagnosis

  

OK

  

Upgraded software

  

Print the diagnosis reports and keep them

- -

Next step
 

KO

  

Software not updated

  

Print the diagnosis reports before and after the update; keep the printouts available for following checks

- -

Next step
 

5

  

Operation of the LPG injector rail pressure sensor in open air and with engine switched off

  

Diagnosis

  

OK

  

The reported pressure must be about 1 bar

  

Print the diagnosis reports and keep the printouts available for any further check

- -

Next step
 

KO

  

Value remarkably different from 1 bar

  

Replacement of the pressure sensor

- -

Next step
 

6

  

LPG pressure in the injector rail with engine at idling speed and engine water temperature at the operating temperature (higher than 70°C), with LPG fuel supply mode

  

Diagnosis

  

OK

  

The reported pressure must be about 1.2 bar

  

Print the diagnosis reports and keep the printouts available for any further check

- -

Next step
 

KO

  

Value remarkably different from 1.2 bar

  

Restore the rated operating conditions

- -

Next step
 

7

  

Presence of errors involving the oxygen sensor and the throttle body

  

Diagnosis

  

OK

  

No fault

  

Next step
 

KO

  

Error report

  

Restore the rated operating conditions

- -

Next step
 

8

  

Impedance value on the cable from temperature and air pressure sensor to LPG system control unit and to the engine control unit

  

Diagnosis

  

OK

  

Correct value lower than 1 Ω

  

Next step
 

KO

  

Value higher than 1 Ω

  

Cable replacement
 

9

  

Complete LPG fuel supply line

  

1043A04

  

OK

  

No fault

  

Next step
 

KO

  

Obstructions, leaks, fouling, presence of deposits

  

Restore the rated operating conditions

- -

Next step
 

10

  

LPG injector conditions

  

1057B66

  

OK

  

No fault

  

Next step
 

KO

  

Fouling, presence of deposits

  

Clean/Replace

- -

Next step
 

11

  

Conditions of the pressure sensor on LPG injector rail

  

1057B70

  

OK

  

No fault

  

Next step
 

KO

  

Fouling, presence of deposits

  

Replacement

- -

Next step
 

12

  

LPG filter conditions

  

1057B60

  

OK

  

No fault

  

Next step
 

KO

  

Fouling, presence of deposits

  

Replacement

- -

Next step
 

13

  

Intake air duct conditions

  

1048^^

  

OK

  

No fault

  

Next step
 

KO

  

Obstructions, leaks, fouling, presence of deposits

  

Restore the rated operating conditions

- -

Next step
 

14

  

Conditions of the spark plugs

  

5510D10

  

OK

  

No fault

  

End of diagnosis
 

KO

  

Fouling, deposit of carbon, irregular colour

  

Clean/Replace all spark plugs.

NOTE

Keep the removed plugs and return them to be analysed (it is compulsory to attach also some well focused pictures, stating the cylinder corresponding to each plug).