XC90 2.5T AWD L5-2.5L Turbo VIN 59 B5254T2 (2003)
The module will be set to a resting mode and no functions will be performed, such as setting the mirror or operating the power windows
Power seat module (PSM):
The memory function in the seat will not work. Stored positions for seats and mirrors will not work when the car is unlocked with a remote control
Upper electronic module (UEM):
The seat belt reminder will be lit, even though the belt is secured in the seat belt buckle. It will not be possible to lock or unlock the car using the remote
Audio module (AUM):
The radio retains most of its functionality. However, the buttons on the steering wheel will not work
Rear electronic module (REM):
The fuel gauge is not working and it will not be possible to lock/unlock the rear doors using the central locking switch. The heating loops in the rear
windshield and the rear folding head restraints will not work
Steering wheel angle sensor module (SAS):
The anti-skid system will not work
Steering wheel module (SWM):
Buttons on the steering wheel and the turn signal lamp stalk will not work. However the horn will still work because it is connected directly to the central
electronic module (CEM).
Some clear examples for the high speed network:
Cannot be started as a result of no communication between the central electronic module (CEM) and transmission control module (TCM) + engine
control module (ECM)
Electronic throttle module (ETM):
The node has three Limp-home levels:
Level 1: No cruise control function
Level 2: Accelerator pedal "heavy". Poor response
Level 3: Present Limp-home mode. The engine speed (RPM) is controlled via the injectors.
Transmission control module (TCM):
It is not possible to use all the gears.
Note! If the control module has gone into Limp-home due to an open-circuit in the CAN communication, the functionality will not return
during the cycle, even in the event of the fault disappearing.
Anti-lock brake system module(ABS)/Brake control module (BCM):
The remaining functionality depends on what fault has occurred. In the event of a fault in the AYC sensor, the indicator lamp lights and DSTC stops
working. Faults in the wheel sensors cause the indicator lamp to light and the ABS function to disappear, although there is still braking assistance. The
unit can lose certain diagnostics in Limp-home mode
Central electronic module (CEM):
Extremely large loss of function. It is worth noting that the control module has separate circuits for the high speed and low speed networks. This means
that it is possible to communicate with the control module via the high speed network even when the low speed network has a fault.
If the central electronic module (CEM) has stored diagnostic trouble code (DTC) CEM-DF14 CAN low short-circuit to ground, this doesnotmean that
the central electronic module (CEM) is necessarily the control module which short-circuits the cable. The short-circuit may be from any part of the cable
to any ground terminal or ground lead. The fault may be in a cable harness, which is the most common situation, or in a control module. Note that the
diagnostic trouble code (DTC) can be stored in some control modules but not in others, and that the short-circuit in this case can be far from the control
module that stores the diagnostic trouble code (DTC).
Statistically there is a high likelihood of the fault being in the cable harness (check behind the audio module (AUM), at the supplemental restraint system
module (SRS), the terminals for the CAN cables in the connectors on the transmission control module (TCM) and the engine control module (ECM).
Note that terminal pins (P/N 9441394) can be used to check the mating surface in the female connectors for the CAN cables. If the mating surface is
defective or the terminal pins detach too easily, the female connector socket must be replaced (P/N 9442486).
If diagnostic trouble code (DTC) E001 is stored continually and the cable harness is free of faults, all control modules containing diagnostic trouble code
(DTC) E001, apart from the central electronic module (CEM), must be disconnected from the CAN network. Delete the diagnostic trouble codes (DTCs)
in the remaining control modules and read off diagnostic trouble codes (DTCs) again to see if the fault disappears. Then connect the control modules
again, one by one, until the diagnostic trouble code (DTC) recurs. If VIDA can communicate with the car when the ignition key is in position 0 and 1 but
not in position 2, the fault is probably in a 15-supplied control module.
The above method can also be used in other scenarios. On rare occasions, control modules can begin sending irrelevant messages on the CAN network.
This can prevent the correct messages from getting through. The result can be one or more E003 or CEM-1A51 to 1A66 diagnostic trouble codes
(DTCs). It may be difficult to determine which control module is causing the interference. In this case, the above method may be the only way of finding
the fault source.
If none of the control modules on the LS-CAN respond but a response is received from the control modules on HS-CAN
The central electronic module (CEM) protects the CAN network from short-circuits caused by the data connection device. This is achieved with the aid
of four internal relays, one for each CAN cable. The relays are closed when the central electronic module (CEM) receives a signal from VIDA on the