Tr Signal/EKP Relay

The EKP relay switches on as soon as DME control unit outputs at pin No. 1 a ground signal with superimposed engine speed signal (once per crankshaft revolution). In addition, at ignition on, EKP relay is briefly activated by DME in order to build up necessary fuel pressure before starting. Voltage increase can be measured at fuse No. 23. Possible causes:

• Wire to EKP relay defective.
• EKP relay or main relay defective.
• Voltage supply for DME control unit, DME relay 1 or 2 defective.
• No signals from engine speed/position sensor. See Figure .