We have years of experience tuning Ford engines to optimise for performance and efficiency. The process. We analyse your vehicle and can adjust the engine management programme, also known as the ECU (Engine Control Unit). This engine software is largely responsible for the behaviour of the Transit Connect 1.5 TDCi 100hp engine and its fuel Turn the ignition off and plug back in the CKP sensor to the harness connector. Set your DMM to a low DC voltage setting so that you can read millivolts. Touch the DMM black lead to battery negative. Then, using the meter red lead, back probe the black ground wire at the harness connector or CKP sensor. RFwwVH.