If you want to read it right, just reverse the leads. Place the positive lead in #2, and the negative in #3. That should give you the 70.
Read from that point on. And make sure of it.
If you read 30 (KOEOff), any fault values will be opposite on the fault codes table once the engine is running.
You may get a fixed 70% and start looking for what it means, when in reality your fault code is a 30%.
An example of fault codes:
70% - No TD/TN siganl. Open circuit in wiring at KE unit.
30% - Coolant temperature sensor faulty.
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car