23 · Diagnostics

Air bag failure warning light on

Make: Alfa Romeo
Model: 159 Factory Service Manual
Year: 2005–2011
Section: Instrument panel › Air bag failure warning light on

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Fault diagnosisAir bag failure warning light on

AIR BAG FAILURE WARNING LIGHT ON

The brake fluid warning light remains on with the handbrake released.

N.B.: The (negative) brake fluid level signal is sent by the sensor to the Body Computer Node which makes it available via the B-CAN 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 appropriate message is displayed.

0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the EXAMINER diagnostic equipment and check the following at the CAN INFORMATION: No control units inactive No faulty control units No control units with faulty CAN	Move on to Step 1	1. Fault on CAN network	1. Continue following the instructions for the diagnostic equipment
		Move on to Step 1	2. Impossible to converse with the Body Computer	2. Move on to Step 2
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner connected, check the plausibility of the brake fluid level parameter at the Body Computer Node	Move on to Step 4	1.The parameter is not plausible	1.Replace body computer Op. 5505A32 BODY COMPUTER - R.R
		Move on to Step 4	2.Impossible to connect to the Body Computer control unit	2.Move on to Step 2
2	ELECTRICAL POWER SUPPLY CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the electrical power supply for the Body Computer Node is correct	Move on to Step 3	Electric power supply positive and/or earth faulty	Replace defective component (in the case of a fuse, find out what caused it to blow).
3	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Using the Examiner, check whether it is possible to connect to the Body Computer Node.	Move on to Step 4	Impossible to connect to the Body Computer control unit	Replace Body Computer Op. 5505A32 BODY COMPUTER - R.R
4	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis	The fault persists	Move on to Step 5
5	BRAKE FLUID LEVEL CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the brake fluid level is not low	Move on to Step 9	Insufficient brake fluid level	Move on to Step 6
6	BRAKE FLUID LEVEL TOP UP	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Top up the brake fluid level and check that the warning light goes out	End of diagnosis	The warning light does not go out	Move on to Step 7
7	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the diagnostic equipment connected, check that there are no CAN faults at the BRAKE NODE	Move on to Step 8	Fault on C-CAN	Move on to Step 13
8	ELECTRICAL SYSTEM CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Disconnect the connector from the oil level sensor and check that it is working properly See E4010 INSTRUMENT PANEL See table X01 EXCESSIVE FUEL CONSUMPTION	Move on to Step 9	Brake fluid level sensor defective	Replace the sensor Op. 3330A30 DEVICE SIGNALLING BRAKE FLUID LEVEL - CHECK DEVICE ON TANK - INCLUDES REPLACING CAP AND TOPPING UP LEVEL, IF NECESSARY
9	ELECTRICAL SYSTEM CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the continuity of the cable from the connector to the Body Computer See E4010 INSTRUMENT PANEL	Move on to Step 10	Lead broken	Restore the correct connection.
10	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner and check that plausibility of the handbrake applied parameter at the Body Computer Node	Move on to Step 11	The parameter is not plausible	Proceed as instructed by the See table K072 HANDBRAKE APPLIED WARNING LIGHT
11	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner or keep it connected and check the operation of the brake fluid level warning light in active diagnosis at the Instrument Panel Node	Move on to Step 12	The warning light does not flash	Replace instrument panel Op. 5560B10 CONTROL PANEL - R+R
12	ELECTRICAL POWER SUPPLY CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the electrical power supply for the Instrument Panel Node is correct	Move on to Step 13	Electric power supply positive and/or earth faulty	Replace the defective component (in the case of a fuse, find out what caused it to blow). 13
13	ELECTRICAL CONNECTIONS CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the electrical connections betwen the Body Computer and the Instrument Panel, in particular that each individual pin is correctly connected.	Move on to Step 14	Electrical connections not working.	Renew the damaged electrical connections.
14	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner connected, check the plausibility of the brake fluid level parameter at the Body Computer Node	Move on to Step 15	The parameter is not plausible	Replace body computer Op. 5505A32 BODY COMPUTER - R.R
15	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis

‹ Prev Abs and handbrake warning lights both on Next › Handbrake warning light does not come on (with handbrake applied)

Parts & tools for this job For 2005 Alfa Romeo 159

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