T27 rear caliper arm position?

[Mark 57]

2011 Avensis estate. 2.0d

Have recently developed the ‘check parking brake system’ warning on the dash. Is intermittent but more so when parked on an incline. Code that comes up is C13a7. I know this points to the actuator which can water can leak into but wondering if/what mechanical elements can also create this code?

There has been no recent work carried out to the rear brakes since a year ago when it had pads, discs and a n/s calliper and fine since then. Both handbrake arms on the callipers appear to move freely and return with operation. What I have noticed is the position of the o/s caliper with the arm resting up against the bolt when handbrake is on. The n/s sits in the middle. Does this mean it’s not operating properly? 

Will reset but comes back on. Handbrake operates normal but with warning ⚠️ 

In addition to this I read somewhere about the torque values being either 0 or around 1200nm with 2000 meaning an electronic issue? Mine reads 2022 min and 2044 but not constantly. 

Any info or advice appreciated. Hoping to get wheels off tomorrow to look further. Car has done 180k so not worth trying an actuator as so expensive. Thanks 

[jimtaxi]

Having recently replaced both rear calipers,disks and pads I noticed that the clevis pins were worn, a groove had formed where cable connection end bears on it when tensioned ,also the cable end the hole where the clevis pin fits through was elongated so all this wear adds up to a significant amount of extra travel.I replaced clevis pins which helped. I have not had any warning on dash since replacements were fitted.The whole EPB system is complicated and can become unreliable due to wear. Why rear calipers were not the same type as VW with small stepper motor fitted and no complicated wire tension system,it spoils what for me has been an ultru reliable car.

[Mark 57]

Thanks for reply. Was considering trying a new o/s calliper to eliminate any possible wear issues and positioning of the arm but will check pins etc too thanks. Worth a try as car runs fine in all other areas!