V70 XC AWD L5-2.4L Turbo VIN 56 B5254T (1998)
Control Module HVAC: Description and Operation
Communication and Programming With ECC Control Module
The air conditioning system's control module is connected to the diagnostic test point, and its diagnostics conform to the new diagnostics concept.
It is also possible to program the control module with certain functions by means of the Volvo System Tester via the diagnostic test point.
The control module can identify 38 different faults and hold 10 faults in memory.
The control module also has in-built emergency programs for most types of faults.
If a fault develops on the air conditioning system the orange-colored light-emitting diodes for the A/C and recirculation flash for 20 seconds to warn
the driver. The diodes also flash for 20 seconds every time the ignition is turned on, and/or when the engine starts.
If the fault is intermittent there is no flashing when the fault is not present. Faults on the sun sensor give no error indication.
If the damper motors on a new control module have not been self-adjusted, or if programming has changed the green light-emitting diode for the A/C
Self-adjustment can be activated in 2 ways:
Via the diagnostic test point, by means of the Volvo System Tester.
Driving the car above 30 km/hr (19 mph) for at least 15 seconds and charging the generator (D+ signal high).
NOTE: It the green A/C diode is not flashing self-adjustment can only be carried out using the Volvo System Tester.
During self-adjustment the green light-emitting diode for the A/C flashes.
If self-adjustment fails an error code is stored in the control module, and the orange diodes give an error indication.
The control module automatically checks the following components following self-adjustment:
Normal function of the fan.
The readings from the sensor and control signals are within acceptable limits.
Reading Error Codes; Erasing Error Codes
The Volvo System Tester is used to read error codes, counters, rolling values and to erase error codes, via diagnostic test point.
The control module can be programmed for different chassis and equipment, allowing one and the same control module to be used for all cars. This
means that if the control module is replaced it must be adjusted for the car in order to function normally.
Programming is carried out via the diagnostic test point using the Volvo System Tester.
The control module can be programmed with the following parameters: