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)

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ABS/ASR Control Unit

There are several different control units available. To prevent interchanging control units there are two lugs cast in control unit connector and at front clasp there is a notch located in different positions for different model/engine combinations.
Control unit receives input from four wheel speed sensors, stop lamp switch, electronic accelerator control unit (for throttle valve actual position), snow chain switch and pressure reservoir switch. control unit turns these input signals into output signals for following components: hydraulic unit solenoid valves, relays (solenoid valves, return/pressure pump and ASR charging pump), electronic acceleration control unit, ASR indicator lamp, snow chain switch LED, ABS warning lamp and ASR warning lamp. From input signals control unit differentiates between three operational modes, normal operation, ABS operation and ASR operation.