|  |  | Results of the tests | 
| 0 | PRELIMINARY CHECKS | All OK | Problems met | Operation | 
|---|
|  | Check
the operation of the direction indicators / hazard warning lights:
if one of the bulbs is not working, the intermittent operation of
the others is affected | Continue to Step 1 | The direction indicators
do not work at all | See table    I10 | 
| 1 | STEERING COLUMN SWITCH UNIT INTERMITTENT
OPERATION CHECK | All OK | Problems met | Operation | 
|---|
|  | Check
that the steering column switch unit is working properly: in particular,
the intermittent device in the actual unit:  see DESCRIPTION AND OPERATION: 5550A stalk unit | Continue to Step 2 | Intermittent switch faulty | Replace intermittent switch | 
| Stalk unit not working properly | Replace the steering column switch unit  Op.   5550A12 | 
| 2 | CHECKING CORRECT OPERATION | All OK | Problems met | Operation | 
|---|
|  | Check
that the fault is no longer present | End of diagnosis | Fault persists | Search for the
fault starting from another symptom' |