Checking Supply Voltage/Ground Terminal, Climate Control Module (CCM)

Checking the supply voltage/ground terminal

Power supply, climate control module (CCM)
The climate control module (CCM) is powered via the power input on the control module. When the ignition is on, the power input is powered and the control module is in active mode.
1. Power input 1 (terminal #C1-1 (#25)) is supplied with power via a fuse from the battery. This power input is used to power the memory in the control module. In the event of an open-circuit, the control module will be reset and adaptation values and diagnostic trouble codes (DTCs) will disappear.

Checking the power supply
Check the power supply cable from the battery to the Climate control module (CCM) terminal #C1-1(#25). Check for an open-circuit. Check for loose connections, contact resistance and oxidation. Check the fuse. The voltage must be approximately battery voltage.

Ground terminal, climate control module (CCM)
The climate control module (CCM) has a ground input. See the relevant wiring diagram for further information about the ground terminal.
- Ground input (#C1-16 (#40)) is a power ground and is connected to the ground terminal in the body.

Checking the ground terminal
Check the ground cable. Check for loose connections, contact resistance and oxidation. Check for an open-circuit. With the ignition on, the drop in voltage between the ground connection for the control module and the ground terminal must not be greater than 0.5 V.
Remedy as necessary.

Other information
- Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- Signal specification Signal Specification, Climate Control Module (CCM)
- See the relevant wiring diagram for information about circuits and ground terminals in the bodywork.
- Checking wiring and terminals Checking Wiring and Terminals. Permanent Faults

Continue - DONE

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