TestBook was a diagnostic and service-information platform developed through a partnership between Rover Group and Hewlett-Packard's Integrated Systems Division. HP's 1994 employee magazine describes the custom instrument as introduced by Rover in September 1993. It was designed around both vehicle diagnosis and repair information rather than fault-code reading alone. Hewlett-Packard, Measure, September–October 1994.
Hardware and functions
HP described a rugged computer with a 486 processor, flat-panel touch screen, CD-ROM drive, vehicle communications interface and digital instruments. The 1996 Range Rover service manual describes diagnostic self-tests and associated equipment including a breakout box, data flight recorder and engine analyser module. Its technical information included wiring schematics, component locations, service bulletins and workshop manuals. HP history; 1996 Land Rover Range Rover service manual.
T4 and T4H
The related T4 system combined a handheld tester, diagnostic port, laptop and adapters. Land Rover's workshop documentation refers to TESTBOOK/T4 for diagnosis, and its T4 manual lists a TestBook-1 exchange kit. In October 2015, JLR announced the standalone handheld T4H kit for servicing earlier Land Rovers in place of TestBook and T4; the release was headed “all pre 2008MY”, but the appropriate vehicle and system should still be checked against its application information. Land Rover T4 user manual; JLR T4H special tool release, October 2015.
Vehicle context
TestBook was used for Land Rover as well as the wider Rover Group context described by HP. Later Jaguar and Land Rover diagnostic practice used IDS, Symptom Driven Diagnostics (SDD), Pathfinder and TOPIx Cloud Diagnostics, with overlapping model and system coverage. Check the actual vehicle, market, model year and service procedure before selecting equipment. See Jaguar and Land Rover diagnostics and IDS.
The same diagnostic family was also used by MG and Rover: the MG Rover Group T4 manual identifies both marques. See MG Rover diagnostic systems; brand-specific application coverage must be checked. MG Rover T4 manual.