Diagnosis

DIAGNOSIS

System self-diagnosis

Self-diagnosis aims to reveal faults in the following components:

A warning light on the control panel will not necessarily come on if a fault occurs.

If sensors are not working, the system implements signal reconstruction strategies (recovery) in order that engine and catalytic converter can function adequately but without experiencing further damage

In this condition, the vehicle can be driven to a service centre for the necessary repairs.

Once the fault has been corrected, the warning light will go off

Any fault that occurs is memorised temporarily by the system control unit in order to facilitate repairs. When the ignition key is removed, these are transferred to the permanent memory where the can be read by a Fiat/Lancia Tester.

Diagnosis using Fiat/Lancia tester

Connect the Fiat/Lancia Tester (F.L.T.) to a socket beside the ECU.

Information is exchanged between ECU and Tester via two test lines (K e L); the communication protocol follows ISO 8 standards. Line K is two-way while line L is one-directional (from Tester at control unit).

The protocol is Master-Slave type sustained at 4800 baud on K line; dialogue is activated by directing to 5 bits on line L.

The Tester is connected to the ECU as follows:

1. Connect the Fiat-Lancia Tester using «ADAPTER ADT 101 A»
2. Activate TESTER either through the cigar lighter or by connecting directly to the battery (a special extra lead is provided for this purpose).
3. Connect the Tester socket to the test socket.

The Tester is able to perform the following functions:

• Engine parameter display
• Error display
• Active diagnosis