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Fiat Croma Factory Service Manual (2005-2010)22 · Fault diagnosis
22 · Diagnostics

Vehicle protection system warning light on constantly

Make
Fiat
Model
Croma Factory Service Manual
Year
2005–2010
Section
Instrument panel › Vehicle protection system warning light on constantly
Fault diagnosisVehicle protection system warning light on constantly

VEHICLE PROTECTION SYSTEM WARNING LIGHT ON CONSTANTLY

The Engine Control Node sends a message via the C-CAN network to the Body Computer, which makes it available via the B-CAN network, to the Instrument Panel node.

Faults in the C-CAN network will turn on the warning lights of the control units that communicate on this network. Verification of the CAN Network Information is intended to detect this situation

1PRELIMINARY CHECKSALL OKPROBLEMS ENCOUNTEREDACTION

Check whether the eobd warning light is on at the same time as the vehicle protection warning light. In this case, check:

  • Possible incorrect key code
  • Fault in engine control node
  • CAN line inactive
Move on to Step 21. Both warning lights on due to an incorrect immocode fault1. Move on to Step 2
2. Engine Control Node inactive and/or incorrect2. Identify the inactive control units on the network
3. Fault on CAN network3. Move on to Step 9
2CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION

With the Examiner connected to the Teg Reader node, check for faults in the key recognition device system.

In active diagnostic mode, check the ignition key is enabled and recognised.

Move on to Step 31. Key recognition device faulty1.Replace the key recognition device
2. Ignition key with defective/incorrect transponder2. Restore the operation of the ignition key
3ELECTRICAL POWER SUPPLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the power supply to the Body Compute Node is correct and the wiring between the nodes. Check in particular that each individual pin is correctly connected.Move on to Step 41. Fault in positive electrical supply and/or earth1. Replace defective component (in the case of a fuse, find out what caused it to blow).
2. Electrical connections not operational2. Restore the damaged wiring to correct operation.
4CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Use an Examiner to check the possibility of connection to the Body Computer NodeMove on to Step 5Impossible to connect to the Body Computer.

Replace Body Computer

Op. 5505A35 MAIN BODY COMPUTER/JUNCTION UNIT - R.R.

5CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Using the Examiner diagnostic equipment check, in Instrument Panel mode, that there are no errors and that the parameters are present.Move on to Step 61. System fault1. Move on to Step 6
2. Fault on CAN network2. Move on to Step 13
3. Presence of errors3. Continue as described by the diagnostic equipment
6ELECTRICAL POWER SUPPLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the electricity supply to the node is correct. Check the wiring between the Body Computer and the Instrument Panel. In particular, check that each individual pin is properly connected.Move on to Step 71. Fault in positive electrical supply and/or earth1. Replace defective component (in the case of a fuse, find out what caused it to blow).
2. Electrical connections not operational2. Restore the damaged wiring to correct operation.
7CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Using an Examiner check, in Instrument Panel mode, that there are no errors and that the parameters are present.Move on to Step 8Fault persists

Replace the Instrument Panel

Op. 5560B10 CONTROL PANEL - R+R

8ACTIVE DIAGNOSIS CHECKALL OKPROBLEMS ENCOUNTEREDACTION
With the Examiner in Instrument Panel Node mode, check that the vehicle protection warning light is correctly activated in Active Diagnosis.Move on to Step 9The warning light does not flash

Replace the Instrument Panel

Op. 5560B10 CONTROL PANEL - R+R

9CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION

Keeping the diagnostic instrument connected, check the Engine Control Node for the absence of:

  • System/component faults
  • Faults in the CAN network/s
Move on to Step 121. System/components faulty1. Move on to Step 10
2. Fault on CAN network2. Move on to Step 13
3. Presence of errors3. Continue following the instructions for the diagnostic equipment
10ELECTRICAL POWER SUPPLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the electricity supply to the node is correct. Check the wiring between the Body Computer and the NCM. In particular, check that each individual pin is properly connected.Move on to Step 111. Fault in positive electrical supply and/or earth1. Replace defective component (in the case of a fuse, find out what caused it to blow).
2. Electrical connections not operational2. Restore the damaged wiring to correct operation.
11CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Using an Examiner check, in Engine Control Node mode, that there are no errors and that the parameters are present.Move on to Step 12Fault persists

Replace the Engine Management Control Unit

Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R

12ACTIVE DIAGNOSIS CHECKALL OKPROBLEMS ENCOUNTEREDACTION
With the Examiner in Engine Control Node mode, check that the vehicle protection warning light is correctly activated in Active Diagnosis.Move on to Step 13The warning light does not flash

Replace the Engine Management Control Unit

Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R

11CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Using an Examiner check, in Engine Control Node mode, that there are no errors and that the parameters are present.Move on to Step 12Fault persists

Replace the Engine Management Control Unit

Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R

12ALL OKPROBLEMS ENCOUNTEREDACTION
With the Examiner in Engine Control Node mode, check that the vehicle protection warning light is correctly activated in Active Diagnosis.Move on to Step 13The warning light does not flash

Replace the Engine Management Control Unit

Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R

13ELECTRICAL POWER SUPPLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the node power supply/electrical connections are correct. Check the (network) wiring between Engine Control, Body Computer and Instrument Panel. Check, in particular, that each individual pin is correctly connected to each node.Move on to Step 141. Fault in positive electrical supply and/or earth1. Replace defective component (in the case of a fuse, find out what caused it to blow).
2. Electrical connections not operational2. Restore the damaged wiring to correct operation.
14CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer presentEnd of diagnosis

Parts & tools for this job For 2005 Fiat Croma

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