22 · Diagnostics

Airbag failure warning light on

Make: Lancia
Model: Ypsilon Factory Service Manual
Year: 2003–2011
Section: Instrument panel › Airbag failure warning light on

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Fault diagnosisAirbag failure warning light on

AIRBAG FAILURE WARNING LIGHT ON

The brake fluid warning light remains on with the handbrake not applied.

The (negative) brake fluid level signal is sent by the special sensor to the Body Computer Node which makes it available via the B-CAN network to the Instrument Panel Node.

The Instrument Panel Node lights up the dedicated warning light and displays the insufficient brake fluid level message; if the warning light is faulty the relevant message is displayed.

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Connect the EXAMINER diagnostic equipment and check the CAN NETWORK INFORMATION: For inactive control units For control units with errors For control units with CAN errors	Continue to Step 5	Presence of fault in the CAN	Continue as instructed by the tester
		Continue to Step 5	Impossible to converse with the Body Computer	Continue to Step 2
1	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Keeping the Examiner connected, check the plausibility of the brake fluid level parameter at the Body Computer Node	Continue to Step 4	The parameter is not plausible	Replace the Body Computer Op. 5505A32 Continue to Step 7
		Continue to Step 4	Impossible to connect with the Body Computer control unit	Continue to Step 2
2	ELECTRIC POWER SUPPLY CHECK	All OK	Problems met	Operation
	Check that the Body Computer Node electrical power supply is correct.	Continue to Step 3	Positive and/or earth electrical power supply fault.	Replace the defective component (if a fuse is involved, search for the cause of the problem).
3	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Using the Examiner, check the possibility of connecting with the Body Computer Node.	Continue to Step 1	Impossible to connect with the Body Computer control unit	Replace the Body Computer Op. 5505A32
4	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	The fault persists	Continue to Step 5
5	BRAKE FLUID LEVEL CHECK	All OK	Problems met	Operation
	Check that the brake fluid level is not low	Continue to Step 9	Brake fluid level too low	Continue to Step 6
6	TOP UP BRAKE FLUID LEVEL	All OK	Problems met	Operation
	Restore the brake fluid level and check that the warning light goes out	End of diagnosis	The warning light does not go off	Continue to Step 7
7	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Keeping the diagnostic equipment connected, check that there are no CAN errors at the BRAKE NODE	Continue to Step 8	Presence of faults at the C-CAN	Continue to Step 14
8	CHECKING ELECTRICAL EQUIPMENT	All OK	Problems met	Operation
	Disconnect the connector from the fluid level sensor and, using a multimeter, check the efficiency of the connection to earth See E4010 INSTRUMENT PANEL	Continue to Step 9	Faulty earth	Restore earth connection efficiency See E4010 INSTRUMENT PANEL
9	CHECKING ELECTRICAL EQUIPMENT	All OK	Problems met	Operation
	Check the continuity of the cable from the connector to the Body computer See E4010 INSTRUMENT PANEL	Continue to Step 10	Cable broken	Restore connection See E4010 INSTRUMENT PANEL
10	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the Examiner and check the plausibility, at the Body Computer Node, of the handbrake applied parameter	Continue to Step 11	The parameter is not plausible	Continue according to the instructions for the See table K72 HANDBRAKE APPLIED WARNING LIGHT
11	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Connect the Examiner or keep it connected and check the operation of the brake fluid level warning light at the Instrument Panel Node through active diagnosis	Continue to Step 12	The warning light does not flash	Replace instrument panel Op. 5560B11
12	ELECTRIC POWER SUPPLY CHECK	All OK	Problems met	Operation
	Check that the Instrument Panel Node electrical power supply is correct.	Continue to Step 13	Positive and/or earth electrical power supply fault.	Replace the defective component (if a fuse is involved, search for the cause of the problem).
13	CHECK ELECTRICAL CONNECTIONS	All OK	Problems met	Operation
	Check the electrical connections between the Body Computer and the Instrument Panel, in particular that each individual pin is correctly connected.	Continue to Step 14	Electrical connections not working.	Restore damaged electrical connection.
14	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
	Keeping the Examiner connected, check the plausibility of the brake fluid level parameter at the Body Computer Node	Continue to Step 15	The parameter is not plausible	Replace the Body Computer Op. 5505A32
15	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists	Replace the brake fluid reservoir and sensor Op. 3330C30

The airbag fault warning light is controlled directly by a dedicated connection to the Instrument Panel Node from the Air Bag control unit

1	CHECK WITH DIAGNOSTIC EQUIPMENT	All OK	Problems met	Operation
		Results of the tests
	Connect the diagnostic equipment and check that there are no system/component faults in the Air Bag control unit	Continue to Step 2	System/component fault	Continue according to the instructions for the diagnostic equipment
2	ELECTRICAL EQUIPMENT CHECK	All OK	Problems met	Operation
	Check the continuity and the insulation of the fault warning light control lead from airbag control unit to instrument panel See E7030 AIRBAG	Continue to Step 3	Wires in o.c. or s.c.	Renew the wiring See E7030 AIRBAG
3	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists	Change airbag control unit Op. 5580C14

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Parts & tools for this job For 2003 Lancia Ypsilon

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