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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 turned on, was then on for at least 10 seconds and then turned 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 fault 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-related and other information can be displayed by the Volvo Scan Tool (ST) connected to the data link connector (DLC) under the center console cover. The Volvo Scan Tool (ST) communicates with the control module via a standardized interface.
A detailed Description of the Volvo Scan Tool (ST) is contained in the Service Manual Volvo Scan Tool (ST).

Volvo on-board diagnostic (OBD) system




Using the Volvo Scan Tool (ST) it is possible to:
- read off and erase diagnostic trouble codes (DTCs), counters and frozen values
- continuously monitor the value and status of system 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:
- the ignition must be ON
- the battery voltage must be normal.

Note! For self-adjustment of the damper motors the engine must be running at idle (generator (GEN) charging).

Connecting the Volvo Scan Tool (ST)




To connect the Volvo Scan Tool (ST):
- Ignition off.
- install memory cassette
- Connect the Volvo Scan Tool (ST) with a cable to the data link connector (DLC) located below the center console cover.
- Ignition on.
- Turn on power to the Volvo Scan Tool (ST).
- Select language, car and group of functions using a multi-function menu.
- select the system required using the multi-function menu
- select function from another multi-function menu:
- select DIAGNOS TEST to read and erase diagnostic trouble codes (DTCs) and self-adjust the damper motors
- select MONITOR TEST to continuously read off the values and status of control module input and output signals.
- select PROGRAM to program control module with information
- select ADJUST MOTORS to activate self-adjusting on the damper motors.
- select READ CM : ID to display the control module part number.

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 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:
- Blower fan switch, position.
- Voltage generator (GEN) D+, status
- Left temperature selector, position
- left temperature control selector, position
- right temperature control selector, position
- REC buttons, status
- Damper Motor Position Sensor recirculation, position
- Damper Motor Position Sensor air distribution, position
- Voltage generator (GEN) D+, status
- 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 signal (VSS), value
- fan passenger compartment temperature sensor, status
- communication power unit blower fan motor, status
- Control module control of blower fan, value
For further information about parameters, see scrolling values Scrolling values ECC Scrolling Values ECC.

Reading off and 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. For further information see Description of ECC programmed data Description of ECC Programmed Data.

Self-adjustment of damper motors




This service initiates self-adjustment of the climate unit damper motors. For further information see Self-adjustment of the damper motor limit positions (ECC) Self-Adjustment Of the Damper Motor Limit Positions (ECC).

Note! For self-adjustment of the damper motors the engine must be running at idle (generator (GEN) charging).

Reading control module identification
The Volvo Scan Tool (ST) identifies control modules by reading a code from the memory of the module. This code contains information about the control module part number.

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