Hello all,

My brother's car's abs pump will not stop even after turning the car off. I scanned it and this is the only code seen. We've tried disconnecting the battery for a short while to see if it comes back on when reconnecting, which it does. On older year cars, there seems to be a black box with relays located right by the abs pump on the drivers side firewall, but this is not there on his car. I didn't see one marked as ABS in any of the three fuse boxes.

Does anyone know where this relay is on a 2012? I'd like to locate and test it next.

 

On the G37 the relay is built into the ABS actuator control unit, it's the black box part of the ABS valve block sandwiched between the ABS block and the firewall. It has the single big harness going into it.

Try using a drift and a mallet and GENTLY tapping on the housing in a few places (wooden dowel and a hammer works great) to see if you can unstick the relay.

Typically you replace the whole thing when one goes bad, the ABS motor, valve block, control unit. As one assembly, fortunately they're not terribly expensive, usually around $250 from an online vendor but it's easy to pull the component so if you can get one locally at a pick-n-pull I'd definitely go that route. Brand new they're super expensive though...

I'm sure it can actually be disassembled, I've never done it though.

 

TY for the info Cleric; why am I not surprised they integrated them into the unit in such a way as to render them unservicable?

 

Knowing how Nissan typically builds stuff the relay is probably soldered onto a PCB inside that black box. You might be able to fix it without replacing the entire thing though if you're comfortable desoldering a relay. I'm betting the black box attaches via a stab in direct harness onto the ABS block without any external wiring. I looked up some pics of used ones and it's just a few screws holding what looks like a cover on and the solenoids aren't visible so they must all be inside along with the relay.

I've gotten REALLY creative in the past "fixing" relays by using a dremel tool to cut a little window in the side so the contact points were exposed, vacuum thoroughly to get any plastic debris out, then using plastic safe electrical contact cleaner to clean the inside, then just blow everything out with compressed air and put it in a bag of rice overnight to absorb any excess moisture (don't get the rice into those windows you make in the relay though lol, just set the whole thing on top of the rice and zip the bag up). Wrap electrical tape around the relay windows to seal it up when you're done.

Normally when a contact fails it's because of buildup on the contact points, if they're accessible you can use some sandpaper to sand off irregularities in the surface (only takes a few passes with sandpaper), eventually the buildup gets bad enough that the contact essentially welds itself shut and sticks closed. Tapping on the case with the hammer and drift can break it free, opening up a window in the casing and prying it apart then contact cleaning the points works as a more long-term fix.

It looks like you can pick up a used one for as cheap as $75 though so it's probably not worth disassembly and fixing. Get a motive brake bleeder to make quick work of the brake bleed job and I'm betting the V36 chassis G35 has the same non-standard brake bleed order as the V36 and V35 chassis G35 cars (i.e. not furthest to closest wheel) so definitely look that up before you try bleeding the brakes or they just won't bleed out properly.