Injection control unit voltage

Aug 25, 2006 3 Replies
M

Does anyone know what voltage ICUs work on?



'Er Micra's reverse light switch doesn't work and it also has a second function which is to indicate neutral to the ICU. There's no continuity in the switch(es) when the car's in neutral or reverse so it/they must be buggered.



I tested for voltage on one side of the input to the switch(es) and there's



12v on one pin, which I'm assuming is for the reverse light, but only 4.6v on the other, neutral, pin so I wondered if ICUs work on 5v perhaps? I hope so because otherwise I'm into 'lectric fettling and I don't like 'letrics.

Si


Vote
Twitter Facebook LinkedIn
C

Internally they work on 5v and some external sensors also run 5v but i would have thought a straighforward switch would have been a 12v thu. Without the wiring diagram i cant be more specific im afraid.

Vote
Twitter Facebook LinkedIn
P

Neutral switch pulls down to earth.

4-5v is correct when ign is on and not in neutral. 0v when in neutral and ign on.

Reverse has 12v feed to switch when ign is on. If you don't get 12v on other side of switch when in reverse then switch is faulty. If you do get 12v on both wires from switch but no reversing lamp then bulb or wiring fault.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Vote
Twitter Facebook LinkedIn
M

Thank you kindly.

There's voltage at both feed pins of the connector plug when the ignition's on but when I test the other half of the connector there's no continuity in either the neutral or reverse switches, when in neutral or reverse obviously. Seems odd that they've both failed but I haven't taken it out to see how it works because the gear oil will fall out :)

Si Si

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required