car manufacturers, and by sports and luxury cars produced in small quantities, such as Porsche 928. The most common variants are LH 2.2, which uses an Intel 8049 (MCS-48) microcontroller, and usually a 4 kB programme memory, and LH 2.4, which uses a Siemens 80535 microcontroller (a variant of Intel's 8051/MCS-51 architecture) and 32 kB programme memory based on the 27C256 chip. LH-Jetronic 2.4 has adaptive lambda control, and support for a variety of advanced features; including fuel enrichment based on exhaust gas temperature (ex. Volvo B204GT/B204FT engines). Some later (post-1995) versions contain hardware support for first generation diagnostics according to ISO 9141 (a.k.a. OBD-II) and immobiliser functions. Mono-Jetronic (1988–1995) Digital fuel injection. This system features one centrally positioned fuel injection nozzle. In the US, this kind of single-point injection was marketed as 'throttle body injection' (TBI, by GM), or 'central fuel injection' (CFI, by Ford). Mono-Jetronic is different from all other known single-point systems, in that it only relies on a throttle position sensor for judging the engine load. There are no sensors for air flow, or intake manifold vacuum. Mono-Jetronic always had adaptive closed-loop lambda control, and due to the simple engine load sensing, it is heavily dependent on the lambda sensor for correct functioning. The ECU uses an Intel 8051 microcontroller, usually with 16 KB of programme memory and without advanced on-board diagnostics (OBD-II became a requirement in model-year 1996.) See also Motronic References External links History of the D-Jetronic System Volvo enthusiasts. The site mostly focuses on 240-series cars with the Bosch K-Jet fuel injection systems Fuel injection systems Embedded systems Power control Engine technology Automotive technology tradenames Robert Bosch GmbH