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.
1987 BMW 325eFACTORY OEM SERVICE PROCEDURE
Test 6: MOTRONIC Control Unit
- Check power supply. Turn on ignition. Connections 18 and 35 of control unit have approximately 12 volts. Connections 5, 16, 17 and 19 are connected to ground.
- Pull off relay 2 and bridge terminals No. 87 and 30. This will supply voltage to control unit. If necessary, check activation or replace relay 2. Turn on ignition and check voltage (12 volts) on terminals No. 85 and 86.
- In order to ensure that source of defect is only in control unit, it is recommended to replace DME unit (Motronic Control Unit) for comparison. In addition, perform various L-Jetronic test using BMW service test unit first, depending on type of complaint.
Factory Service Tools
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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.
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