Signal Too Low. Permanent Fault

Signal too low. Permanent fault

Checking connectors and bus wire

Note! Remember that the CAN network is only a communications network. There are therefore no fuses, switches and sensors on the CAN bus. Check the resistance as described below (see references).

Note! To maintain the correct values the battery should be disconnected when measuring resistance.

Check the bus wire for a short circuit to ground as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check the intermediate connectors for contact resistance and oxidation as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Hint: If the fault is found before all the wires below are checked, press Continue.

The following wires and connectors should be checked to locate the short circuit.

Wire between:
- road traffic information module (RTI) 10A and rear electronic module (REM) 15A.
To connect the test box to the RTI control unit, see
To connect the test box to the REM control unit, see
- rear electronic module (REM) 14A, driver information module (DIM) 8 and intermediate connector 54/40.
To connect the test box to the REM control unit, see
To connect the test box to the DIM control unit, see Connecting the Driver Information Module (DIM) test box Connecting the Driver Information Module (DIM) Test Box
- central electronic module (CEM) 3D and driver information module (DIM) 8.
To connect the test box to the CEM control unit, see Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
To connect the test box to the DIM control unit, see Connecting the Driver Information Module (DIM) test box Connecting the Driver Information Module (DIM) Test Box
- power seat module (PSM) 2B and driver information module (DIM) 8.
To connect the test box to the PSM control unit, see Connecting the breakout box, power seat module (PSM) Connecting the Breakout Box, Power Seat Module (PSM)
To connect the test box to the DIM control unit, see Connecting the Driver Information Module (DIM) test box Connecting the Driver Information Module (DIM) Test Box
- driver information module (DIM) 2 and climate control module (CCM) 14A.
To connect the test box to the DIM control unit, see Connecting the Driver Information Module (DIM) test box Connecting the Driver Information Module (DIM) Test Box
To connect the test box to the CCM control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
- audio module (AUM) 7A and climate control module (CCM) 14A.
To connect the test box to the AUM control unit, see Connecting the breakout box, Audio control module Connecting the Breakout Box
To connect the test box to the CCM control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
- phone module (PHM) 22A and climate control module (CCM) 14A.
To connect the test box to the PHM control unit, see
To connect the test box to the CCM control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
- passenger door module (PDM) (driver door module (DDM) on right-hand drive car) 2A, climate control module (CCM) 14A and intermediate connector 54/11.
To connect the test box to the PDM/DDM control units, see Connecting the breakout box Connecting the Breakout Box
To connect the test box to the CCM control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
- climate control unit (CCM) 13A and steering wheel module (SWM) 9.
To connect the test box to the CCM control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
To connect the test box to the SWM control unit, see Connecting the breakout box Connecting the Breakout Box, Steering Wheel Module (SWM)
- steering wheel module (SWM) 10 and supplemental restraint system (SRS) 23B.
To connect the test box to the SWM control unit, see Connecting the breakout box Connecting the Breakout Box, Steering Wheel Module (SWM)
To connect the test box to the SRS control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
- supplemental restraint system (SRS) 24B, upper electronic module (UEM) 3 and intermediate connector 54/13.
To connect the test box to the SRS control unit, see Connecting the breakout box Pinout Values and Diagnostic Parameters
To connect the test box to the UEM control unit, see Connecting the breakout box Connecting the Breakout Box
- driver door module (DDM) (passenger door module (PDM) on right-hand drive car) 2A, upper electronic module (UEM) 3 and intermediate connector 54/10.
To connect the test box to the DDM/PDM control units, see Connecting the breakout box Connecting the Breakout Box
To connect the test box to the UEM control unit, see Connecting the breakout box Connecting the Breakout Box

Additional information
- The voltage should be between approximately 2.0V and 3.5V.
- For wiring diagram for bus wire and for position of connectors see Service Handbook, Section 3, Wiring Diagram.
- To disconnect the battery, see Battery, disconnecting Battery Disconnecting










Continue - Verification

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Verification




Verification

Verification

Hint: After the repair it is necessary to check that the fault has been rectified.








- Ignition off.
- Connect connectors, install components, etc.
- Ignition on for at least 10 seconds.
Check that diagnostic trouble code status is showing Intermittent.





Is the status of the diagnostic trouble code Intermittent?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - Fault Found

VERIFICATION FAILED - Information

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Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - No Fault Found

Attempt New Test - Checking connectors and bus wire

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