Andrew Revill’s Caterham / MG Rover K Series Projects

I have gathered together below all of the technical articles I have written on the Rover K Series engine management, Caterham K Series engine and Caterham K Series electrical wiring diagrams. These articles were all previously uploaded to other sites but bringing them together here has allowed me to ensure that all of the diagrams can be downloaded at full resolution etc.

I hope you find at least some of them useful. I have spent most of my spare time for the last year on the MEMS3 Reading/Writing/Flashing/Remapping projects alone. My main objective is to get as much of this information as possible into the public domain for the general benefit of the Caterham / Lotus / MG Rover communities and to support keeping our K Series cars on the road in the years to come. For this reason I have provided all of this free of charge and on a shareware basis. Feel free to download anything useful and to share around as you see fit. If you have found this to be helpful and feel the urge to show your appreciation, please feel free to use the PayPal Donate button below.

You can email me at

For anyone looking for support for older Rover MEMS ECUs, including MEMS versions 1.2, 1.3, 1.6, 1.9 and 2J, I highly recommend you take a look what James Portman has been doing over at Amongst other things, he has developed some very neat modules which can render the earlier ECUs remappable. James and I have been comparing notes between MEMS3 and MEMS2J and the family resemblances are striking. A lot of the code is identical, which has meant we have been able to support each other on our journeys. Big thank you to James.

MEMS3 Tools

This is my free suite of tools for working with the Rover MEMS3 ECU. It includes MEMS3 Mapper, with full support for remapping (and now live mapping) the ECU, plus support for dual maps with live switching and a utility to reliably recover a bricked ECU. It also includes the simpler MEMS3 Flasher for reading, writing and cloning ECUs and MEMS3 Terminal for monitoring, decoding and logging OBDII communications with the ECU. These tools are all provided free of charge (you just need to purchase a cheap VAG COM KKL 409.1 cable or similar, details provided in the main article here) and run on Windows XP or later, 32-bit or 64-bit.

MEMS3 Internal Calculations

Reverse-engineered documentation for ECU internal calculations.

MEMS3 Map & Firmware Library

A library of standard map and firmware files for MEMS3 ECUs for use with Rover K Series engines (including Caterham 1.6, 1.8, RoadSport, SuperSport and VVC variants and a wide range of MG Rover vehicles) and Land Rover Td5 engines (including Discovery and Defender models). These can be downloaded and flashed onto standard MG Rover and Land Rover ECUs of the appropriate part number (usually available cheap on eBay etc.) using the free MEMS3 Mapper or MEMS3 Flasher tools in the MEMS3 Tools suite. I have not included proprietary remapped files – just genuine original Caterham, MG Rover and Land Rover maps and firmwares.

The format of the file names is:

Vehicle_Type_Capacity - Injector - Author - NNN_Part_Number - NNW_Part_Variant - Firmware_ID - Map_ID.mm3

ZCS Code Checksum Generator

Simple, free spreadsheet for calculating the checksums needed when entering new or updated ZCS codes on Rover 75 and MG ZT cars. The ZCS codes need to be updated whenever the vehicle configuration changes. In the past, people have had to pay significant sums of money for a one-off service to calculate the new checksums. With this simple spreadsheet you can calculate your own. Instructions and explanation included.

Other Caterham / MG Rover EU3 Engine Management Projects

Write-ups of some of my other projects relating to MG Rover K Series EU3 engine management, including cloning ECUs (by physically removing and copying the memory chips – this can now be done more easily using MEMS3 Mapper), building bench equipment to test and program ECUs and work I have done on the Lucas 5AS immobiliser. I’ve included some useful information on the connectors and terminals for the 5AS in this section.

Caterham K Series Engine Wiring Loom Projects

Detailed documentation of the Caterham EU2 and EU3 engine wiring looms. Redrawn and corrected copies of Caterham’s original wiring diagrams. Details of the multifunction relay units (MFRUs). Details on the conversion of MG Rover engine wiring looms to Caterham specification, and conversion of non-VVC engine wiring looms to VVC specification. Recommended crimping tools and settings for terminals used in the engine wiring looms. Details of the Caterham starter motor solenoid circuit with advice on diagnosis of common failures. Fuel pump diagnosis with an oscilloscope.

Caterham K Series Main Vehicle Wiring Loom Projects

Redrawn and corrected copies of Caterham’s original wiring diagram for the main vehicle loom. Details of the indicator and hazard light circuit. Wiring a flick-wipe switch.

Caterham / MG Rover EU3 Engine Mechanical Projects

Simple process for correctly timing the VVC system, with pictures. Making a fuel pressure regulator tester. Details of the positive crankcase ventilation system on the Rover K Series engine. A write-up of a suggested repair and replacement procedure for the jiggle valve in the aluminium inlet manifold, which is often found to be missing on second hand engines.

Gauge Magic

A simple, effective, flexible and cheap solution to making any moving coil gauge work accurately and linearly with any sender. All designs, plans, device firmware and Windows configuration utility are downloadable for free. Parts kits and complete units available to purchase.