VOLVO
IEM-U1A0087 - Private Communication Network. Bus Signal / Message Failures. Missing message
System
Unknown System / Manufacturer Specific
Volvo models this fault code applies to
Applies to the following models:
1 modelV60 (2011–)
Show models by year and engine (2)
What does this fault code mean?
The electric rear axle drive module (IEM) monitors its internal functions and the communication with the clutch control for the electric rear axle (DCC). The code is stored when the internal communication is disturbed or missing, or when communication between the IEM and the DCC is disturbed. The fault is only checked once the test has started at ignition on.
Possible causes
- CAN communication between the IEM and the clutch controller for the electric rear axle (DCC) is faulty
- Software fault in the clutch control for the electric rear axle (DCC)
- The clutch in the electric rear axle ERAD has mechanical damage
- Software error in the electric rear axle drive module (IEM)
- Internal fault inside the ISC voltage converter
What you can do
- 1Read out, note and clear the code, then road test to see whether it returns
- 2Have a workshop check that the connectors to the IEM and the clutch control are fully engaged and free from corrosion
- 3Have a workshop with diagnostic equipment check the communication between the IEM and the clutch control and update the software if needed
- 4If clutch damage is suspected, have a workshop check the clutch in the electric rear axle
- 5Do not work on the electric rear axle or its high voltage system yourself; have a workshop carry out those checks
Symptoms you may notice4
- Warning symbol and text message in the display
- PURE drive mode disengages by itself or is not available
- AWD drive mode disengages by itself or is not available
- HYBRID drive mode runs with the combustion engine active all the time or too often
What the fault can affect3
- With the clutch open, electric propulsion is not possible
- With the clutch open, brake energy recovery from the electric rear axle ERAD is not possible
- With the clutch closed, vehicle speed is limited
General guidance for car owners. Diagnosis on the car can point to a different cause.