Toyota HiAce TEMS System — What It Is & Why It’s Disappearing
If you’ve owned or imported a classic diesel HiAce (especially late ‘80s to mid ‘90s), you may have come across something called TEMS. It sounds advanced—and for its time, it was.
What is TEMS?
TEMS stands for Toyota Electronically Modulated Suspension. It was Toyota’s early version of adjustable suspension, allowing drivers to switch between comfort and performance modes.
In simple terms:
- Electronically controlled shock absorbers
- Switch between soft and firm ride
- Controlled via dash button or ECU
How it works
Each shock absorber contains an internal adjustable valve. The system changes damping by activating that valve electronically.
- Soft mode → smoother ride, more comfort
- Hard mode → tighter handling, less body roll
The full system includes:
- TEMS shocks (front & rear)
- Wiring harness
- Control module
- Dash switch
For a van in the late 80s/early 90s, this was cutting-edge.
Why it’s no longer manufactured
Today, TEMS is effectively discontinued.
Toyota has stopped producing:
- OEM TEMS shocks
- Electronic control components
- Replacement modules and wiring
Why it disappeared:
- Aging vehicle platform
- Low global demand
- Complex and expensive to produce
- Replaced by newer suspension technologies
Bottom line: sourcing new TEMS parts today is extremely difficult, if not impossible.
What this means for HiAce owners
If your HiAce still has TEMS:
- The shocks are likely worn out or leaking
- Electronics may be failing or unresponsive
- Replacement parts are scarce
Common problems:
- Stuck in one mode
- No response from switch
- Blown or soft shocks
The simple solution (most important part)
Here’s the key thing most people don’t realize:
✅ Standard (non-TEMS) shocks from the same-year HiAce bolt in directly.
No modification needed.
That means:
- Same mounting points
- Same fitment
- Direct replacement
You can remove TEMS entirely and run conventional shocks with zero issues.
Why most owners delete TEMS
- Modern shocks perform better anyway
- No electronics = more reliable
- Parts are easy to source
- Lower long-term cost
For real-world use (travel, camping, daily driving):
A quality gas shock setup will outperform aging TEMS systems every time.
Bottom line
TEMS was:
- Innovative
- Ahead of its time
- A cool piece of Toyota engineering
But today:
It’s outdated, unsupported, and impractical to maintain.
The good news:
You’re not stuck with it. Direct-fit standard shocks make upgrading simple.
