The Alfa Romeo 159 can experience ABS problems, generating the trouble code C1275, which is the result of an ABS/ESP control module software fault. Technicians should consider this when diagnosing suspected ABS sensor faults. The fault can illuminate the ESP and/or the ABS warning light. However, the control module will need a replacement if a software issue is found.
Technicians may also be tempted to replace ABS sensors to cure an ESP related fault on these cars when the ESP warning light is illuminated. However, if fault code C1131 (ABS brake fluid pressure sensor, implausible signal) is recorded, the ABS hydraulic modulator will need to be replaced, not the ABS sensor.
EML illumination and an associated camshaft sensor fault code could be the result of a worn camshaft drive chain on the 2.2 diesel engine version. As the chain wears, the camshafts go further out of synchronisation and are picked up by the ECU, which identifies it as a fault. Technicians replacing the camshaft sensors in an attempt to resolve this issue will have wasted both time and money since the camshaft sensors will still be functioning correctly.
Poor running, usually related to loss of power, can be attributed to a sticking EGR valve or a failing MAF sensor on the diesel engine cars. As the two components can produce similar symptoms, technicians should monitor live readings from the engine management system to ensure correct diagnosis.
The 159 can suffer from oil pressure switch problems too, which is a very popular part for this vehicle. Technicians looking to trace oil leaks should bear this part in mind when they start their diagnostic routine.
Engine management temperature sensors are another popular part for the Alfa Romeo 159. Poor starting, hot or cold, high fuel consumption and flat spots could all be indications that this sensor is beginning to fail.