ABS/VDC issues

[aaronpnz]

Evening all, got some issues with my ABS and VDC, as in they seem to have failed and won't pass WOF.

 

Initially, the VDC light came on, fault code showed as faulty steering angle sensor. This light comes on straight away when car is started. 

 

ABS light is now on, sometimes after a while of driving, sometimes straight away. 

 

Scan showed 2 codes, one of which was steering angle sensor, but have been able to (with mechanic) verify sensor is working, but not able to reset and clear code.

 

2nd code is C0074, master cylinder pressure switch. My Legacy is an NZ new BP5 GTb wagon. No one appears to sell the sensor separate, and no one appears to have the correct ABS module either. The switch is a Bosch 0265005303and the ABS module has the number 27536AG050 on it.

 

Can anyone weigh in with advice or even one of these parts, getting desperate as WOF expires next week.

 

Cheers all

 

Aaron

 

 

 

Edited October 3, 2019 by aaronpnz
spelling

[Andy_Mac]

 

 

Wonder if there's a loose connection behind the steering wheel, that would explain it coming and going and not getting found by the mechanic when testing. Could try get one from a wreck to try out I guess.

 

Does the handbrake light stay on once the handbrake is released?

 

The stop light switch seems to come up quite a bit with abs/vdc codes so might be worth checking too.

 

 

I was hoping to find the pressure switch in the wiring diagrams to see if you could just bridge it out to see what would happen but can't seem to find what each pin is other than that there is 3.

 

Amazon looks to have the pressure sensor based on that number, but it's a bit pricey.

https://www.amazon.com/Bosch-Brake-Pressure-Sensor-0265005303/dp/B003NDZJIO

[aaronpnz]

Awesome, thanks @Andy_Mac

 

The handbrake light doesn't light at all, just the ABS and VDC lights. My mechanic uses a decent scanning tool that reads all the ECU's in the car, and borrowed another to be sure. I haven't tried Subaru themselves tho, thier SSM scanner might show different perhaps, might try that.

 

Found a pressure switch on AliExpress under $100 NZD, I'll try that first, otherwise I've located an ABS pump with switch for $300 at a wrecker. 

 

I have a love/hate relationship with this car. 

[aaronpnz]

*sigh* ended up getting the ABS pump from the wrecker, hasn't arrived yet... see how that goes I guess.

[aaronpnz]

So, ABS pump fitted, bled etc... sorted the ABS issue ok, but the VDC issue persists. I can reset the ECU and on restart, it looks good, VDC light stays off, can turn VDC on and off all good. However, at next restart, it's baaaack... VDC lights up immediately. 

Unable to pass WOF as it is, so I have a perfectly *good* car that cannot be driven (legally). Just picked up a cheap Mazda 6, no cambelt to worry about, and will park the Legacy up for a bit while I decide what to do with it. Might sell it  as is even. Dunno. 

Unless there's a genius out there who can give advice on what might cause this issue.

*sigh*

[Andy_Mac]

So the VDC code shows up as an ECU rather than TCU code correct? 

Obviously not the right way to fix it but could you not just pull the ROM, disable that particular code then flash the modified one back?