VOLVO
SUM-0091 - Supply, sensor. Signal too low
System
Suspension Module (SUM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007)
Show models by year and engine (7)
What does this fault code mean?
The supply voltage to the position sensor at the left rear wheel is too low. The supply comes from the suspension control module, and the fault may be in the wire, the connector, the sensor or the control module.
Possible causes
- Ground fault in the supply wire to the sensor
- Poor contact in the connections
- Defective position sensor
- Defective control module
What you can do
- 1Read out the fault codes first. Any code for the left rear position sensor must be repaired and cleared before you continue
- 2Check the connector to the position sensor at the left rear wheel for contact resistance and oxidation
- 3Use a multimeter to check that the power supply to the position sensor has no contact with ground (the car body)
- 4Check that the suspension system fuses are intact; the owner's manual shows where they are
- 5If the wiring is intact, the position sensor or the control module is probably defective. Have a workshop check this
Symptoms you may notice3
- The general warning lamp lights
- Message in the display
- Four-C does not work
What the fault can affect1
- Four-C control is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.