Engine starting circuit check
- Make
- Fiat
- Model
- Grande Punto Factory Service Manual
- Year
- 2005–2012
- Section
- Engine starting › Engine starting circuit check
ENGINE STARTING CIRCUIT CHECK
| STEP | CHECK TO BE PERFORMED | RESOLUTION IF THE CHECK IS NOT OK |
|---|---|---|
| 1 | Connect a charged battery in paralle with the vehicle battery. Start the engine. Move on to Step 6 | Move on to Step 2 |
| 2 | Turn the ignition key to the STARTING position Measure the voltage between pin 30 of the wiring connector (component side) of the starter motor and pin 30 of the wiring connector (wiring side) of the battery , checking that it is less than 0.75 V | There is a high transition resistance between the starter motor and the battery: clean or, if necessary, replace the wiring |
| 3 | Turn the ignition key to the STARTING position Measure the voltage between pin 31 of the wiring connector (component side) of the starter motor and pin 31 of the wiring connector (wiring side) of the battery , checking that it is less than 0.75 V | There is a high transition resistance between the starter motor and the battery: clean or, if necessary, replace the wiring |
| 4 | Turn the ignition OFF. Visually inspect the mechanical engine components connected to the alternator belt, checking that there are no faults | Repair or, if necessary, replace the mechanical component in question |
| 5 | Replace the starter motor Op. 5520B10 STARTER MOTOR - R+R The test can be considered over | |
| 6 | Turn the ignition key OFF. Turn off all the electrical users. Check the battery charge, carrying out the TP_5530B] |
All the vehicle systems should be switched off during these tests. Close the doors and the tailgate, disconnect the engine compartment lighting
| STEP | CHECK TO BE PERFORMED | RESOLUTION IF THE CHECK IS NOT OK |
|---|---|---|
| 7 | Disconnect the cable loom connector from the battery. Measure the current between pin 31 of the wiring connector (component side) and the same pin for the wiring connector (wiring side) of the battery , checking that it is less than 60 mA | The stall current for one or more consumers is too high |
During the search for faults in the wiring, the sections of the wiring for the allocated connectors can be separated. When the stall current moves to the permitted value, after the section has been separated, this means that the fault is located in this section of the wiring
| STEP | CHECK TO BE PERFORMED | RESOLUTION IF THE CHECK IS NOT OK |
|---|---|---|
| 8 | Connect the cable loom connector to the battery. Start the engine. Switch on all the electrical consumers. Let the engine speed reach 3000 rpm. Measure the voltage between pins 30 and 31 of the battery wiring connector (wiring side) , checking that it is less than 12.5 V | Replace the battery |
| 9 | Turn the ignition key OFF. Turn the ignition key ON. Check that the recharging warning light is on. Move on to Step 12 | Move on to Step 10 |
| 10 | Turn the ignition key OFF. Disconnect the cable loom connector from pin D+ of the alternator. Connect a shunt cable with a fuse between pin D+ of the alternator wiring connector (wiring side) and the earth. Turn the ignition key ON. Check that the recharging warning light is off | Replace the alternator. |
| 11 | Repair or, if necessary, replace the electrical wiring between the alternator, all the components that are disconnected from the cable loom during these tests for locating faults and the earth. See E5010 STARTING AND RECHARING The test can be considered over | |
| 12 | Turn the ignition key OFF. Disconnect the cable loom connector from pin D+ of the alternator. Turn the ignition key ON. Check that the recharging warning light is on. Move on to Step 11 | Move on to Step 13 |
| 13 | Turn the ignition key OFF. Measure the voltage between pin B+ of the alternator wiring connector (wiring side) and Earth, checking it is greater than 11 V | Repair or, if necessary, replace the electrical wiring between the alternator and the battery |
| 14 | Check whether there is a high transition resistance between the starter motor and the battery: clean or, if necessary, replace the wiring | Replace the alternator. |
| STEP | CHECK TO BE PERFORMED | RESOLUTION IF THE CHECK IS NOT OK |
|---|---|---|
| 1 | Connect a charged battery in paralle with the vehicle battery. Start the engine. Move on to Step 13 | Move on to Step 2 |
| 2 | Turn the ignition key OFF. Disconnect the cable loom connector from the engine management control unit connector A. Do not engage any gear. Turn the ignition ON. Connect the emergency starting lead for a maximum of 3 secs. between pin 72 (wiring side) of the control unit See M010 ENGINE MANAGEMENT ECU and the earth, checking that the engine does not start | Replace the engine management control unit |
| 3 | Turn the ignition OFF. Extract relay T18 from the engine compartment junction unit (it is the top one in the middle row). Turn the ignition key ON. Measure the voltage between Pin 86 of the base unit and Earth, ensuring it is less than 0.3 V. Move on to Step 5 | Move on to Step 4 |
| 4 | If faults are present, repair or, if necessary, replace the electrical wiring between the engine management control unit and the engine compartment junction unit. See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT The test can be considered over | Replace the engine compartment junction unit Op. 5505A13 ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R. |
| 5 | Turn the ignition OFF. Measure the resistance between pin 72 (wiring side) of the control unit See M010 ENGINE MANAGEMENT ECU and pin 86 of the base for relay T18, checking that it is less than 5 Ohm | Move on to Step 4 |
| 6 | Measure the voltage between Pin 30 of the base unit for relay T18 and the earth, ensuring it is greater than 11 V. Move on to Step 8 | Move on to Step 7 |
| 7 | If faults are present, repair or, if necessary, replace the electrical wiring between the battery and the engine compartment junction unit. The test can be considered over | Replace the engine compartment junction unit Op. 5505A13 ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R. |
| 8 | Connect the emergency starting lead for a maximum of 3 secs. between pins 30 and 87 of the base for relay T18 checking that the engine does not start. Move on to Step 12 | Move on to Step 9 |
| 9 | Measure the resistance between pin 87 of the base for relay T18 and pin 50 wiring side of the starter motor , checking that it is less than 5 Ohm. Move on to Step 11 | Move on to Step 10 |
| 10 | If faults are present, repair or if necessary replace the electrical wiring between the engine compartment junction unit and the starter motor See E5010 STARTING AND RECHARING The test can be considered over | Replace the engine compartment junction unit Op. 5505A13 ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R. |
| 11 | If faults are present, repair or if necessary replace the electrical wiring between the battery, starter motor and earth See E5010 STARTING AND RECHARING The test can be considered over | Replace the starter motor |
| 12 | Turn the ignition ON. Measure the voltage between Pin 85 of the base unit for relay T18 and the earth, ensuring it is less than 11 V. Move on to Step 10 | Replace the starter motor |
| 13 | Turn the ignition key to the OFF position and extract it. Turn off all the electrical users. Charge or, if necessary, replace the battery. Disconnect the connector from the battery cable loom. Measure the current between pin A (wiring side) and pin A (component side) of the battery, checking that it is less than 80 mA. Move on to Step 15 | Move on to Step 14 |
All the vehicle systems should be switched off during the test. Close the doors and the tailgate, disconnect the engine compartment lighting.
| STEP | CHECK TO BE PERFORMED | RESOLUTION IF THE CHECK IS NOT OK |
|---|---|---|
| 14 | The stall current for one or more consumers is too high. During the search for faults in the wiring, the sections of the wiring for the allocated connectors can be separated. When the stall current moves to the permitted value, after the section has been separated, this means that the fault is located in this section of the wiring. The test can be considered over | |
| 15 | Reconnect the connector to the battery cable loom. Start the engine and switch on all the electrical consumers. Let the engine speed reach 3000 rpm. Measure the voltage between pin A and pin B of the battery (wiring side), checking that it is less than 12.5 V | Replace the battery |
| 16 | Turn the ignition key OFF. Disconnect the connector from the alternator cable loom. Turn the ignition key ON. Measure the voltage between pin D+ (wiring side) of the alternator and the earth, checking it is greater than 11 V | Move on to Step 18 |
| 17 | If faults are present, repair or if necessary replace the electrical wiring between the battery, alternator and earth See E5010 STARTING AND RECHARING The test can be considered over | Replace the alternator. |
| 18 | If faults are present, repair or if necessary replace the electrical wiring between the alternator and the engine management control unit | Replace the engine management control unit |
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