Alfa Romeo
146 164 166 1999 models onwards. Suffer intermittent immobiliser faults. Its generally believed in the trade, if the immobiliser control box sees a control voltage below 10v. Be the cause of the volt drop be, hard cranking, battery changes or common shorts in door radial circuits. It scrambles the code grabbing function! Some reset themselves after a long period with the battery connected, up to three days, no joke*. Others will need to go to the main dealer to have codes re-aligned. So if you are changing a battery, keep the control box live above 10v. Its fused up separately, I live up the supply fuse when working on this type of Alfa as a matter of course. Reason being I cannot stand the embarrassment of vehicles driving into our workshop and subsequently being towed away.
*One of our trade customers, a very very competent auto electrician, had one lockout on him, he tried everything to reset it, even entering the over-ride code manually. After waiting three days to get booked into the local Alfa franchise, the morning of the tow-in. It restarted... He had tried daily over the period to restart the 156. I myself have had to wait four to six frustrating hours on several occasions.
146 1998-01 Suffer ECU output problems to MIL (engine management warning light) Output from pin A12 ECU should be 11V for light off and 0.1V for light on, default settings. It is possible to have engine management light illuminated when there is no fault-code due to this problem.
147 Selespeed All models. Suffer gearbox selection module failures which send the system into "limp" only allowing 2nd gear to be selected. Normally no coms to the module is possible with this type of fault. These modules can be fixed at low cost. The bigger problem with the 2.0 twin spark engine is the balance shafts breaking up, throwing the balance shaft belt & cambelt off the pulleys and thus wrecking the engine. Be careful when fitting a new cambelt and balance shaft belt to a rattling engine. It may blow up after a few minutes, when restarted. The tell tale sign is the balance pulley timing marks will be 30 degrees ish off, when you align everything up, before removing the belts. Nobody in the trade in the know, will do the job, due to the risk...
Page updated 28-05-18