Checking Components And Wiring
When too low voltage has been detected, the Central electronic module (CEM) turns off the output to the next ignition cycle. If low voltage has been detected in 200 ignition cycles, the Central electronic module (CEM) is closed by the output until the DTC is erased.
HINT: Erase the diagnostic trouble code, turn off and on the ignition and read out the diagnostic trouble codes again. If the fault has disappeared, the output activates and then the brake light when the brake pedal is depressed. Otherwise the DTC will be stored again.
Check the voltage between the left and right-hand stop lamps and the output on the rear electronic module (REM). The voltage must be approximately 12 V when the stop lamp is activated.
For S60, V70, XC70, and XC90:
Check the cable between central electronic module (CEM) terminal #A15 (15) and rear electronic module (REM) terminal #A18 (18). Check for a short-circuit to ground.
Check the cable between Rear electronic module (REM) and brake lights with regards to short-circuiting to ground.
HINT: Disconnect the cable between the Rear electronic module (REM) and the brake lights to ensure that the cable between the Central electronic module (CEM) and Rear electronic module (REM) is OK.
Remedy as necessary.
Other information
- Central electronic module (CEM): Connecting the breakout box
- Rear electronic module (REM): Connecting the breakout box
- Central electronic module (CEM): Signal specification
- Rear electronic module (REM): Signal specification
- See Central electronic module (CEM), replacing
- For -2004, see: Integrated relay/fuse box cargo compartment/rear electronic module, replacing
- For 2005-, see: Rear electronic module (REM), replacing .
- See Stop lamp, rear windshield, replacing
- See Contents
- Continue
Refer to Verification