Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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 .
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.