Roll Bar: Description and Operation
ROPS diagnostic functions
General
ROPS = Roll Over Protection System.
The ROPS control module has an on-board diagnostic (OBD) system, the Volvo on-board diagnostic (OBD) system, to provide self diagnostic and other information. This can be read off on the VIDA PC connected to the data link connector (DLC) via VCT 2000.
When the ignition is switched on (ignition position I or engine running) the ROPS on-board diagnostic (OBD) system carries out an initial self test. After that, the ROPS on-board diagnostic (OBD) system goes into monitoring mode, carrying out a continuous self test on the system. Continuous self-test on the system. The control module checks for internal faults in all ignition cable outputs and in the output for the ROPS indicator lamp in the combined instrument panel.
Diagnostic trouble codes (DTCs)
If the control module detects a fault it stores a diagnostic trouble code (DTC) and the ROPS indicator lamp light lights. When the ignition is switched on the lamp should light for approximately 5 seconds and then go out if no diagnostic trouble code (DTC) is stored. The control module can store up to 10 diagnostic trouble codes (DTCs). 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 remains in the control module.
Each diagnostic trouble code (DTC) has a total of 4 fault clocks which store information about the start time and any end time for the fault. Both the absolute start and end time are in relation to the total time that the system has been active via the ignition being on. The relative start and end time show the time the fault occurred or disappeared during the time the ignition was last on. The absolute time shows the day and the relative time shows the hours, minutes and seconds. If the fault reoccurs the end time is reset and the fault code counter (counter 2) counts up by 1.
Each diagnostic trouble code (DTC) has a counter (1) which displays if the fault is passive (intermittent) or active (permanent). If the counter value is 0 the fault is intermittent; if the value is greater than 0 the fault is permanent. The counter is uses during fault-tracing which enables easy checking of the fault status; whether it disappears or remains. The diagnostic trouble code (DTC) status bar is updated continuously and switches to intermittent fault if the fault becomes inactive. However if the fault is passive and switches to active, the diagnostic trouble code (DTC) status bar switches to permanent fault.
Reading off Volvo on-board diagnostic (OBD) system
Fault data and other information can be read off using the VIDA PC which is connected via VCT 2000 to the data link connector (DLC)under the center console cover. The VIDA PC communicates with the control module via a standardized interface.
- read and erase diagnostic trouble codes (DTCs), counters and frozen values
- read the value and status of input and output signals.
- read off control module identification.
- reset the system (corresponding to ignition off/on).
- activate the solenoids.
- read off the status of the transit safety catch.
- activate and deactivate transit safety catch.
- read of the number of times the roll-over bars have deployed.
- resest the deployment counter.
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 10 different faults in the form of diagnostic trouble codes (DTCs).
Diagnostic trouble codes (DTCs) cannot be erased before all stored DTCs have been read off at least once during the same ignition phase and the status of all DTCs is intermittent.
Internal diagnostic trouble codes (DTCs) cannot be erased.
Diagnostic trouble codes (DTCs) can be stored for the following fault causes in the roll-over bar circuit:
- short-circuited.
- open-circuit in circuit.
- short-circuit to ground.
- short-circuit to supply voltage.
Diagnostic trouble codes (DTCs) can be stored for the following fault causes in the ROPS warning lamp circuit:
- open-circuit or short-circuit to ground.
- short-circuit to supply voltage.
Reading off input and output signals
Using this function the values and status of the control module input and output signals can be read off.
The following parameters can be read off:
- generator (GEN) voltage D+, status.
- battery voltage.
- energy reserve.
Reading off control module identification
The VIDA PC identifies the control module by reading off a code from the control module memory. This code contains information about the control module P/N.