[Need Help] 2004 Prius in Cambodia - Intermittent 4 Lights, Normal Brake Feel, VSC Once Self-Clear

Hello everyone,

I am a brand new Prius owner (previously only drove gasoline cars) and I'm reaching out for help with a confusing and worrying issue on my recently acquired car. Local shops have given me a unanimous but poorly explained diagnosis, and I'm hoping the collective wisdom here can guide me.

1. Vehicle Info:

• Model Year: 2004 Toyota Prius (2nd Generation).
  
  
• Mileage: Approximately 122,000 miles.
  
  
• Location: Cambodia.
  

2. Problem Description (The Core Issue):
My dashboard intermittently lights up with the following FOUR warning lights all at once (Note: the separate ABS light is NOT on):

• Red Triangle (Master Warning)
  
  
• CHECK ENGINE light
  
  
• VSC light
  
  
• Brake Warning light (the yellow circle with an exclamation mark and parentheses around it)
  

Critical Details & Observations:

1. Normal Brake Feel: Importantly, when the lights are on, the brake pedal feels perfectly normal—no stiffness or change in performance. This seems different from many reports I've read.
   
   
2. Intermittent & Changing: The lights can appear on startup or while driving. On one specific occasion, after all lights were on, the VSC light turned off by itself during a drive the next day, while the other three lights remained illuminated.
   
   
3. Hybrid Battery Gauge Behavior: In daily driving, I've noticed the battery charge indicator (on the multi-segment display) often quickly climbs several segments into the blue (high charge) zone, only to drop back down to just one or two segments (yellow/low zone) shortly after, triggering the engine to charge it again. This cycle repeats frequently.
   

3. What Three Repair Shops Said (The Confusing Part):
I consulted three shops, all concluding "hybrid battery failure" but with varying levels of diagnosis:

• Shop 1: Used a diagnostic scanner. Verbally stated “the computer shows the hybrid battery pack is failing,” but provided no fault codes, battery module voltage data, or any printed report.
  
  
• Shops 2 & 3: Based solely on looking at a photo of my dashboard lights (no scan), immediately said “battery problem.”
  All three recommended a very costly battery replacement. The lack of concrete evidence, especially given the intermittent nature and normal brake feel, makes me deeply skeptical.
  

4. My Research & Why I'm Skeptical:
My reading (including on this forum) indicates that this specific 4-light combination is a hallmark of ABS Actuator/Brake Booster failure in Gen 2 Prii, often due to a faulty pressure sensor/valve (codes like C1241/C1256).

• A failing hybrid battery typically causes persistent drivability issues, not this kind of intermittent, self-clearing (VSC light) electrical fault.
  
  
• My normal brake feel suggests the ABS actuator's hydraulic function may be intact, pointing to an electronic sensor fault within it.
  
  
• The shops' failure to provide any verifiable data (codes or battery module voltages) makes their expensive conclusion hard to trust.
  

5. My Specific Questions to the Community:

1. Has anyone experienced this exact combination: intermittent 4 lights (no ABS light) with normal brake feel, and a VSC light that can self-clear? Was it the ABS actuator or the hybrid battery?
   
   
2. Does the described “quick up-and-down” battery gauge behavior sound normal for a 20-year-old battery, or is it a clear sign of severe capacity loss? As a new owner, I have no baseline for comparison.
   
   
3. What is the definitive diagnostic step? Should I demand the specific ABS/brake system codes or the individual voltage readings of all 28 hybrid battery modules to know the truth? Which is more critical here?
   
   
4. Could these two problems be related? For example, could a weak battery cause unstable voltage that triggers the ABS actuator codes?
   
   
5. Given my location in Cambodia, what is the most sensible and cost-effective path forward? If it's the ABS actuator, is component-level repair (sensor/valve) viable? Are there reliable parts suppliers that ship internationally?
   

Additional Photo (Display Menu):
For reference, here is a photo of my center display screen:
Thank you so much for your time and expertise. Any guidance, shared experiences, or practical advice on how to proceed would be a tremendous help to a confused new Prius owner.