Diagnostic Functions ECC
Diagnostic functions ECC
General
The control module has a built-in diagnostic system, the Volvo on-board diagnostic (OBD) system, which continuously monitors itself and its input and output signals.
Diagnostic trouble codes (DTCs)
If the control module detects a fault it stores a diagnostic trouble code (DTC) and the orange indicator LEDs in the REC and air conditioning (A/C) buttons flashes for approximately 20 seconds. The control module can store up to 38 diagnostic trouble codes (DTCs). If the total diagnostic trouble code (DTC)s exceeds 10 the five first diagnostic trouble code (DTC)s will always be saved, while the last five become the latest diagnostic trouble code (DTC)s to be stored.
If for some reason a fault disappears after the diagnostic trouble code (DTC) has been permanently stored in the control module, information about the fault is stored in the control module.
Every diagnostic trouble code (DTC) has a counter which records the number of cycles which have been " fault-free" since the diagnostic trouble code (DTC) was stored (intermittent fault). A cycle is defined from when the ignition was switched on, was then on for at least 10 seconds and then switched off. Every time the cycle runs without the control module registering the fault again, increases the counter by 1. Using the counter it is possible to determine if the control module interprets diagnostic trouble code (DTC) as permanent or intermittent. When the counter is at 0 the transmission control module (TCM) treats the malfunction as a permanent fault. If the counter value is greater than 0 the control module interprets this as meaning the fault is intermittent.
Reading off Volvo on-board diagnostic (OBD) system
Fault data and other information can be read off using the VIDA PC which is connected to the data link connector (DLC) under the center console cover.
Volvo on-board diagnostic (OBD) system
With the VIDA PC it is possible to:
- read and erase diagnostic trouble codes (DTCs), counters and frozen values
- Continuously monitor the value and status of input and output signals
- self-adjust the damper motors
- program the control module with certain information
- read off control module identification.
To activate the Volvo on-board diagnostic (OBD) system:
- ignition on
- battery voltage normal.
Note! For self-adjustment of the damper motors the engine must be running at idle (generator (GEN) charging).
Reading and erasing diagnostic trouble codes (DTCs)
Stored diagnostic trouble codes (DTCs) and counters can read out and erased using this service. The on-board diagnostic (OBD) system can identify 38 different faults in the form of diagnostic trouble codes (DTCs).
Diagnostic trouble codes (DTCs) can only be erased when all stored diagnostic trouble codes (DTCs) have been read off at least once.
Reading off input and output signals
Using this function the values and status of the control module input and output signals can be continuously read off.
The following parameters can be read off:
- generator (GEN) voltage D+, status
- blower fan switch, position
- air distribution selector, position
- left temperature control selector, position
- right temperature control selector, position
- REC buttons, status
- A/C-buttons, status
- Damper Motor Position Sensor recirculation, position
- Damper motor air distribution position sensor, position
- damper motor position sensor temperature driver side, position
- damper motor position sensor temperature passenger side, position
- sun intensity, value
- passenger compartment temperature, value
- engine coolant temperature (ECT), value
- outside temperature, value
- time since ignition on, value
- vehicle speed, value
- fan passenger compartment temperature sensor, status
- communication power unit blower fan motor, status
- control module control of blower fan, value.
Reading off programming data
This function can be used to read off programmed data and program data into the control module. The purpose of the programming is to adapt the control module to the car version or when the driver requests that certain adjustments are made to the settings.
Note! Before replacing a control module all programmed data must be read off first if this is possible. The information will then be downloaded into the new control module after it has been installed.
The following data can be programmed into the control module or read from it:
- driver position (which side of car driver sits, left-hand or right-hand drive car)
- engine type (indicates if car has gasoline or diesel engine).
- passenger compartment ventilation filter (indicates whether the climate control system has a passenger compartment ventilation filter)
- passenger compartment temperature (adapts passenger compartment temperature in relation to the selected position on the passenger compartment temperature selector).
- blower fan speed (adapts blower fan speed control when the blower fan switch is in the AUT position).
Note! A new control module must be programmed with the driver's position, if it isn't the green LEDs in the REC and AC buttons will flash and the climate control system will not be accessible to regulate the climate in the passenger compartment. After programming the driver position, it is necessary to carry out self-adjustment of the damper motors.
Self-adjustment of damper motors
This service initiates self-adjustment of the climate unit damper motors.
Note! For self-adjustment of the damper motors the engine must be running at idle (generator (GEN) charging).
Reading off control module identification
The control module can be identified by reading off a code from the control module memory. This code contains information about the control module P/N.