Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Coolant Level Sensor

Coolant Level Sensor:






The coolant level sensor, is a solid state module that senses coolant level by means of two probes protruding into the engine coolant.

^ When the coolant is at the proper level, the coolant level signal at the ECM is pulled low (0-3 volts).

^ With low or no coolant, the signal at the ECM will be high (4-5 volts).

^ When the signal voltage is high, the ECM will turn "ON" the low coolant level light.