Lack of power help!!!

[skippye36]

No that's my next and only option left is wiring or ecu, has anyone got a pin diagram for the ecu?

[Grrrmachine]

http://www.e30zone.net/e30zonewiki/inde ... CU_Pinouts

[skippye36]

Thanks

[Fred555]

skippye36

PostPosted: Fri Dec 27, 2013 11:14 pm


Test 1: voltage shut 7.89v
voltage fully open 7.89v
voltage during opening ranging from 7.83 - 7.87 while opening

Test 2: voltage shut 7.93
voltage fully open 7.95

Realise its not showing full 9vollts but sure from what you say that voltage should increase as i open the flap.[

With the missing voltage that you point out are the Engine Wiring Loom splices Corroded? If you measured the voltages again on the same wires but at the ECU end are they still reading low or are they now correct? If correct suspect splices.

Factory made splices were only crimps (and RHD cars have more splices for ignition switch wiring to reach other side) - Also Engine Earth Connections (all of them) clean and remake them - sometimes the under dash loom earth point(s?) near the ECU needs cleaning otherwise there is a voltage differential from different earth connection quality's.

If none of the above - ECU Fault?

[skippye36]

Need to speak to a couple of vehicle electrician friends as my knowledge of vehicle electrics only stretches to the basics.

[Fred555]

Basically set a multi-meter to DC Volts, get longest test leads you have, with engine running put one test prod through the insulation to make contact with the wire inside the insulation on the points you measured mentioned voltages for above & then get a helper to stab the same wire at the ECU end - if you measure any voltage this way the wire or the splice in the wire is kaput - a wire or cable should not measure more than 0.2 Volts (200mV) tested this way and some say that a Sensor connection (for an ECU) should not measure any more than 0.05 (50mV) - the engine has to be operating to make this kind of test meaningful that is the only way to effectively apply a real load to the circuit under test which will only then show the voltage difference when tested because of the applied load - but do the test without the load of the engine running and the test will read zero even if the wire/connection under test is in a terrible condition.