Component Test
PREPARATIONS FOR STANDBY CURRENT MEASUREMENT
When the vehicle enters the usage mode abandoned the control modules and the communication buses are set to sleep mode, which reduces the power consumption. Factors such as whether the vehicle is locked, the alarm is on or off or whether any doors are open affect the rate at which the vehicle will reach standby power consumption. The lowest power consumption is achieved the quickest when the vehicle is locked, the alarm is on and the vehicle's hatches and doors are closed.
Use the tool "Vehicle SoC, voltage and current history" to help determine whether fault tracing of high standby consumption is warranted.
Preparations
- Ensure that all lighting is switched off.
- Ensure that the diagnostic tool is not connected in the vehicle.
- Ensure that there is no key near the vehicle.
- Open the tailgate or trunk lid and bonnet and set the locks to the deadlocked position using a screwdriver for example.
- Open the driver's and passenger doors and set the locks to the deadlocked position using a screwdriver for example.
- Ensure that the power windows are in closed position.
Activate the function for reduced alarm via the Center Console Display (CCD) in order to be able to work inside the center console without risking activation of the alarm.
Close the rear doors, remove the key and lock and alarm the vehicle. If all locks are set to lock position when alarm arming is requested, the vehicle indicates this by flashing the indicators briefly.
Wait until the vehicle has come down to standby current consumption, which can take up to 25 minutes.
Do not open any doors or the test will have to be restarted from the beginning. Be aware that if the vehicle is equipped with foot motion detector module FMDM there is a risk of the workshop personnel accidentally activating the sensor by being directly behind the vehicle, and thus affecting the standby current consumption. Ensure an active connection attempt to the vehicle via the workshop's WiFi is not performed.
- Continue
Refer to: QUIESCENT CURRENT IN CONTROL MODULES
MEASUREMENT METHOD
General
If it is clear that the power consumption is greater than the specified limit values, fault trace by successive elimination.
The method for measuring the total standby current consumption is described below.
The vehicle's standby current is measured using a multimeter.
Connecting the multimeter at the battery negative pole
When measuring the vehicle's total power consumption, connect the measuring instrument in series with the battery at the battery's negative pole.
To avoid current surges that could damage the measuring instrument when the battery cable is connected, carry out the following. Never connect the measuring instrument if the radiator cooling fan is in operation as this can damage the instrument.
- Ensure that the multimeter is equipped with two clamps.
- Check that the multimeter is set for current measurement.
- Connect the clamps to the vehicle's negative poles, as shown in the picture.
- Disconnect the ground point as shown in the picture and put something in between the ground point and the wire in order to keep the connection broken.
Check that the connections are installed correctly. If the circuit is broken, the standby current must be re-checked from the beginning
- Activate the function for reduced alarm via the Center Console Display (CCD) in order to be able to work inside the center console without risking activation of the alarm.
- Disconnect the ground point as shown in the picture and put something in between the ground point and the wire in order to keep the connection broken.
Measuring and reading off the total standby current.
Read off the standby current consumption. The total standby current should be less 25 mA.
If the car is equipped with "Volvo on call" and the standby current is too high, wait 5 minutes and measure again. The "Volvo on call" system is active for short periods and then increases the short-term standby current above the normal value.
Look and listen for unusual vehicle behavior. Check, for example, if a relay is hot, if it is this can indicate that current is flowing through it.
Check, if necessary, that CAN is in inactive mode by ensuring that the voltage on the bus is 0 V in relation to ground. Check, if necessary, that CAN is in inactive mode by ensuring that the voltage on the bus is 0 V in relation to ground.
If a fault is detected, fault-trace the relevant system. Otherwise continue fault tracing by successive elimination.
- Continue
Refer to: QUIESCENT CURRENT IN CONTROL MODULES
FAULT TRACING BY SUCCESSIVE ELIMINATION
During fault tracing by successive elimination, try to localise the problem by measuring the power consumption at the same time as removing one fuse at a time in the vehicle.
Procedure
- Expose the fuse boxes in the engine compartment, in the passenger compartment and in the luggage compartment.
- Use the multimeter and check that the relays and fuses have the correct voltage, use the wiring diagram and signal tables as assistance. Measure between fuses and suitable ground terminals. If a fault is detected, fault-trace the relevant system.
- Remove a fuse and read off the standby consumption according to the instructions above. If the power consumption has dropped to less than 25 mA, fault trace the system that the fuse corresponds to. If power consumption has not reduced, repeat the procedure with another fuse.
Remove one fuse at a time and measure. If possible, prevent replacing fuses before the fault is found because there is a risk of the vehicle exiting usage mode abandoned. If the vehicle still exits usage mode abandoned, repeat the preparations for standby measurement before fault tracing with successive elimination being set.
If the fault has not occurred, continue with successive elimination on relays and the connectors for the vehicle's control modules.
Reinstall the connectors, components etc. Do not forget to unlock the trunk lid or tailgate and doors.
Select "Continue" to exit.