P123C: Charge Air Cooler (Intercooler) Coolant Pump Not Running (Lotus Evora)
Severity: medium
What it means: This is a manufacturer-specific code, so its meaning depends on the make. On the supercharged Lotus Evora 400 and Evora GT, owners report it as 'intercooler pump not running': the electric pump that circulates coolant through the charge-air cooler isn't moving coolant, and the car limits power to protect the engine.
Safe to drive? Drive gently to a safe place. Limp mode protects the engine; don't keep driving hard in hot weather with it set.
Common symptoms
- Limp mode or reduced power
- Warning on the dash, often in hot weather
- Charge-cooler coolant pushed into the overflow tank
Likely causes, ranked
- Low coolant in the charge-air cooler loopDIY
- Air trapped in the charge-cooler loopDIY
- Failed charge-cooler pump or its wiringShop
Advertisement
Vehicle-specific notes
- 2017–2021 Lotus Evora: A 2020 Evora GT owner in Texas heat found all the charge-cooler coolant in the overflow, refilled the loop and got out of limp mode. Read the full answer · Source
DIY or shop?
Topping off and bleeding the charge-cooler loop is DIY. Pump and wiring diagnosis is shop work.
Before you replace parts
- Confirm what P123C means for your make. It's manufacturer-specific.
- On an Evora, check the charge-cooler coolant tank and overflow with everything cool.
- Refill with the correct coolant and bleed air, then clear the code and see if it returns.
- If it returns with the loop full, test the pump's power, ground and the pump itself.
Safety / mechanic note
Verify with a mechanic. Hot intake air from a cooler that isn't working can harm the engine.
Advertisement