Linear Solenoid Valve Calibration FAIL

Here's a post showing the different parts breakdowns and names across Gen 1, 2, 3, and 4. It shows out-of-date pricing, but the names are right.

We kind of all know the freaking names change—not just the names; the actual parts get split up and recombined into different combinations and assemblies.

As anybody posting about a particular car knows what generation of car it is, what makes things easiest for others following along is to be sure to use the names of the parts for that generation.

 

So just an update. Changed the master cylinder for new. Bleeding procedure and linear valve offset learning completed without a hitch and a lot faster than it took with the old parts. Thanks for everyone's reading and inputs.

 

Revising this thread because I wanted to document my situation because it cost me a huge amount of time, and I couldn’t find a complete answer anywhere for the Highlander Hybrid, which behaves differently from the regular Highlander or Prius. (Small disclaimer, I used chatgpt to summarize for a coherent post)

Vehicle: 2006–2010 Toyota Highlander Hybrid
Codes: C1345 (Linear Solenoid Offset Incomplete), sometimes C1368, C1203, C1311, C1313, plus a cascade of solenoid codes
Parts replaced: Brake Actuator / Booster Assembly (44510-48060)

My Symptoms
My actuator went bad, and I replaced it with a used one and manually bled it.

Worked fine but had some noise here and there so I thought, hey I'll just do it the right way with techstream. I ran through all the Techstream procedures. It wouldn't clear, so I upgraded from the mini VCI to a VXDIAD and upgraded from v13 to v18. I performed the following:

• Linear Valve Offset
  
  
• Accumulator Zero Down
  
  
• Master Cylinder Zero Point
  
  
• Stroke Sensor Zero Point
  
  
• Brake Pedal Loads Test
  
  
• ECB Memory Reset
  

Even after completing these successfully, C1345 came back immediately on key cycle, and all ABS/Brake/Trac/VSC lights stayed on. The pump would run when I opened the door, relays clicked normally, voltage was stable, and all sensors showed good data.

I even tried:

• Paperclip (TC–CG) method
  
  
• Multiple battery disconnects
  
  
• Running procedures with and without Techstream 18
  
  
• Checking relays, fuses, pump load resistance
  
  
• Verifying pressures and sensor voltages
  

Still got C1345 every time.

At this point I had replaced the actuator twice, and both units behaved the same. That ruled out the actuator itself.

The Actual Fix
The real problem wasn’t the actuator.

It was the Skid Control ECU.

On the Highlander Hybrid, the skid ECU is separate from the actuator (unlike some Prius generations). The ECU “handshake” or internal pairing with the actuator matters. If the actuator and skid ECU firmware don’t match (or if the ECU has an internal stored fault), the vehicle will not complete the Linear Solenoid Offset procedure, even if it pretends to.

I finally solved the problem by doing this:

I replaced the Skid Control ECU with the one from the same donor vehicle that the actuator came from.
As soon as I installed the matching ECU:

• C1345 cleared immediately
  
  
• All ABS/VSC/Brake lights turned off
  
  
• Techstream procedures completed without failure
  
  
• No stored or pending codes after multiple key cycles
  
  
• Full ABS and traction control functionality returned
  

So the actuator was fine the whole time — it was an ECU pairing/firmware issue.

Important Notes for Others

• The Highlander Hybrid is not wired like the regular Highlander. Some guides for the non-hybrid do not apply.
  
  
• The skid ECU can absolutely cause a permanent C1345 if it cannot complete offset learning.
  
  
• Swapping only the actuator may not be enough.
  
  
• A used skid ECU must be paired with the actuator from the same donor vehicle, or at least have compatible firmware.
  
  
• Dealers often replace both the actuator and ECU together for this exact reason.
  
  
• You cannot “force clear” the handshake in Techstream 18 — only the dealer’s ADVi package can fully re-initialize the pair, but swapping a matched ECU is the DIY workaround.
  

Final Summary
Two different brake actuators gave me the same C1345 because my skid control ECU was the real failure point. Replacing the skid ECU with the one that came with the donor actuator fixed everything instantly.

If you’ve done everything correctly, your actuator tests good, Techstream procedures won’t finish, and you’re stuck on C1345 — look at the skid control ECU. It may be the actual culprit. My recommendation would be to manually bleed it as best as possible, and avoid resetting the memory at all costs.