Diagnostic Functions

Diagnostic functions

General
The rear electronic module (REM) has a built-in diagnostic system, the Volvo on-board diagnostic (OBD) system, which continuously monitors itself and the input and output signals.

Diagnostic trouble codes (DTCs)
A diagnostic trouble code (DTC) is stored if the rear electronic module (REM) detects a fault. The control module can store up to 6 diagnostic trouble codes (DTCs), the 3 first and the 3 latest.

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 memory.

Reading and erasing diagnostic trouble codes (DTCs)
Stored diagnostic trouble codes (DTCs) can be read off and erased using this function. The on-board diagnostic (OBD) system can identify 58 different faults in the rear electronic module (REM) in the form of diagnostic trouble codes (DTCs).

After the diagnostic trouble code (DTC) is stored it can also be read off if the fault is still present (permanent fault), or if the fault has disappeared for any reason (intermittent fault).

Diagnostic trouble codes (DTCs) can only be erased when all diagnostic trouble codes (DTCs) have been read at least once.

Reading off input and output signals
Using this function the values and status of the rear electronic module (REM) input and output signals can be continuously read off.

The following parameters can be read off:
- status of the locking relay and unlocking relay for the left rear door
- status of the locking relay and unlocking relay for the right rear door
- status of the relay for the rear foldable head restraint
- the status of the trunk lid pop-up relay (4 doors)
- status of the locking relay and unlocking relay for the fuel tank filler cover
- status of the rear fog lamp relay
- rear fog lamp relay status, German version and trailer
- status of the back-up lamp relay
- status of the rear windshield heating relay
- power supply to the rear electronic module (REM)
- fuel level, left and right tank halves
- input signal from the pressure sensor (CNG), Full (200bar): 4.5V Empty (0 bar): 0.5V)
- input signal from the temperature sensor (CNG) (5V - 0.5V) (0°C ~ 4.5V, 25°C ~ 3.6V)
- lamp fault. Indicates whether any bulb has blown. Parking lamp groups 1 and 2, cover the left and right rear parking lamps.
- the power supply to the level sensor module (low, high). High when the car is alarmed, otherwise low
- level sensor module, alarm status. Indicates whether the control module for the level sensor has deployed the alarm
- Level sensor module, x/y status. Indicates whether the level sensor module has deployed first in the X or Y axis
- the status of the trunk lid handle, (pop up, no action) (4 doors)
- current, bulb failure warning sensor group 1 (left rear parking lamps). The rear electronic module (REM) detects lamp faults when the current is below 0.6A (4 doors)/0.45A (5 doors)
- current, bulb failure warning sensor group 2 (right rear parking lamps). The rear electronic module (REM) detects lamp faults when the current is below 0.6A (4 doors)/0.45A (5 doors)
- current, lamp fault rear fog lamp. The rear electronic module (REM) detects lamp faults when the current is below 1.5A
- central electronic module (CEM) driver brake (off, on). Checks the input signal from the stop lamp driver from the central electronic module (CEM) to the rear electronic module (REM)
- stop lamp check (lamp on, lamp off). Checks whether the rear electronic module (REM) transmits a signal to activate the stop lamp relay
- current, lamp fault, stop lamp. The rear electronic module (REM) detects lamp faults when the current is below 3.0 A
- status of back-up gear (idle, engaged)
- status of the relay for the tailgate wiper. Controls starting and stopping the tailgate wiper (5 doors)
- status of the relay for extended X-supply. Controls the power supply to the tailgate wiper (5 doors)
- status relay 15i power supply
- status relay gas tank valve
- cargo compartment lighting output signal (0W - 10W)
- position sensor input signal for the headlamp beam height control (1.7V -3.2V)
- calibration status of the position sensor for the headlamp beam height control
- status back-up (reversing) warning system (off/on)
- status diagnostic back-up (reversing) warning system, Parking Assistance Module (PAM) and sensor 1-4
- status seat belt reminder passenger (off/on)
- input signal anode/cathode for seat belt reminder.

Activating components and functions
With this function the components/functions affecting the rear electronic module (REM) outputs can be activated.

The following components can be activated:
- activating the relay, left rear door locking
- activating the relay, left rear door unlocking
- activating the relay, deadlock for the rear doors
- activating the relay, right rear door locking
- activating the relay, right rear door unlocking
- activating the relay, rear foldable head restraint
- activating the relay, tailgate pop-up
- activating the relay, fuel tank filler cap locking
- activating the relay, fuel tank filler cap unlocking
- activating the relay, rear fog lamp
- activating relay rear fog lamp, German version and trailer
- activating the relay, back-up (reversing) lamp
- activating the relay, rear windshield heating
- activating the relay, tailgate wiper (5 doors)
- activating the relay, extended X-supply
- activating the relay, 15I power supply
- activating the relay, gas tank valve
- set assumed fuel level in the left tank half (10, 20, 30 or 40 liters)
- set assumed fuel level in the right tank half (10, 20, 30 or 40 liters)
- set assumed information about bulb failure monitoring (lamp fault)
- activating and deactivating the level sensor module
- check "sleep mode" ("wake up" or "enter sleep") level control module
- assumed signal from the handle, tailgate pop-up
- activate the rear electronic module (REM) alarm trigger
- activate the cargo compartment lighting
- activate the back-up (reversing) warning.

Reading off statistical data
With this function programmed data can be read off. For the rear electronic module (REM), this indicates primarily which relays should be installed.

The following statistics can be read off:
- relay, left rear door locking
- relay, left rear door unlocking
- relay, rear door deadlock
- relay, right rear door locking
- relay, right rear door unlocking
- relay, tailgate pop-up
- relay, fuel tank filler cap locking
- relay, fuel tank filler cap unlocking
- relay, rear fog lamp
- relay, rear fog lamp, German version and trailer
- relay, back-up (reversing) lamp
- relay, rear windshield heating
- relay, increased X-supply
- relay, tailgate wiper
- relay, folding rear head restraint
- relay, 15I power supply
- relay, rear air conditioning (A/C)
- relay, gas tank valve
- relay, RMI 15, reserve
- relay, RMI 11, reserve
- relay, RMI 12, reserve.

Reading off the control module identification
VADIS/VIDA identifies the control modules by reading off a number of codes from the control module memory.

The codes contain information about the control module's:
- hardware P/N (control modules without software)
- hardware serial number (control modules without software)
- software P/N
- diagnostic software P/N
- P/N slave nodes (level sensor module)
- CAN frame period (40 ms for the CAN low-speed network at time of writing)
- Subcontractor identification plate (ECU-ID).