All 4 brakes are fully locked on my 2004 G35 sedan. It has a C1142 code.

I got one of the calipers changed when it seemed that one was locked and got it flushed as well. This did not help.

I swapped out the ABS control module as someone suggested here. It did not help.

I took it to another mechanic and he said the ABS pump needs to be replaced and it needs programming at the dealer and he couldn't do it. I checked with another mechanic and he says it doesn't need programming as long as it's for the same car model. New ABS pumps are hard to come by but used ones are easily available. I ordered a used one, but I'm hesitating to get the work started, because it needs programming I'll still need to get it that done somewhere else.

Any advice?

 

There is no programming for the ABS/VDC/TCS computer.

Unplug the ABS relay and see if it's still locked up, I assume that the car is NOT locked up with the key turned to OFF correct? Your relay is probably stuck closed which is making the ABS motor stay on anytime the key is turned on.

C1142 is a malfunction on the brake pressure sensor, if you unplug the ABS relay (all 3 harnesses on it) then the entire system is disabled and you can start to troubleshoot if it's a mechanical problem like line blockage, or if it's a computer problem.

I'm pretty sure the pressure sensor can be replaced separately. I'm not totally sure because I haven't disassembled the ABS block on the G35/350Z but the pressure sensor should be it's own sensor screwed into the block, probably a three wire harness. Ground reference, power in, signal out.

If you can't figure out where it's at I can check out my G35 later and possibly take pictures if it's visible without removing anything, it's over stored at the shop and I'm heading there later this afternoon.

 

Thank you for getting back to me.

The brakes are locked even when the engine is off and the hand brake is disengaged. I tried disconnecting the relays and still locked.

 

Sounds like there's some kind of physical blockage or catastrophic failure of the ABS block, I would start by disconnecting each of the 4 corners at the ABS block to see if they spin each will spin.

 

By ABS block do you mean this guy?

 

yes pull the lines to one of the calipers and see if it will unlock the caliper. If it does, your issue is the ABS block / pump or upstream from there.

 

Yep, you can see on the block it's engraved with which line is which - RL = Rear Left, RR = Rear Right.

 

Thank you

 

I got the pump replaced. But the problem is still there

 

Did any of the tires spin when you had the lines disconnected?

 

Yes they all did. I could push the car.

 

Did you ever unplug the ABS relay? If the ABS motor is running because the relay is stuck in the closed position then the motor is generating brake pressure without your foot being on the pedal. This will make it feel like the brakes are engaged (they are when the motor is running).

You can hear it running when it's on if you have the hood opened.

 

The motor is not running. My mechanic turned them on when he was bleeding the brakes and I heard them then - so not I know exactly what they sound like. So they are not continuously running. He'd earlier disconnected the relay as well and it didn't release the brakes.

 

Then it's probably the brake master cylinder, there's only a few parts on a brake system. Reservoir, MC, ABS solenoid block, ABS motor and relay, brake lines, caliper.

 

Thank you.