SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-10
SWS DIAGNOSIS
GENERAL DESCRIPTION
BEFORE CARRYING OUT TROUBLESHOOTINGM1549014700710
Before carrying out troubleshooting, check the fol-
lowing two items.
Make sure that the ETACS-ECU, the junction
block (J/B), the front-ECU and the engine com-
partment relay box are connected securely.
Make sure that fuses and fusible links related to
relevant systems are not blown.
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
DIAGNOSTIC FUNCTIONM1549028900245
ON-BOARD DIAGNOSTICS
If an error occurs in the ECU or the SWS or CAN
communication line which performs the SWS or CAN
communication, the DTC is memorized in
ETACS-ECU. The DTCs have 11 items. The DTCs
are checked to connect diagnostic tool MB991958
(MUT-III sub assembly). The memorised DTCs are
not erased even if the ignition switch is turned to the
LOCK (OFF) position. The DTCs are erased to oper-
ate diagnostic tool MB991958 (MUT-III sub assem-
bly).NOTE:
*1: For vehicles that do not have a sunroof,
the diagnosis code is always sent but it does not indi-
cate a problem.
NOTE:
*2: The diagnosis code for the current prob-
lem is not sent.
NOTE:
*3: For vehicles that do not have a multi cen-
ter display (middle grade type), the diagnosis code is
always sent but it does not indicate a problem.
HOW TO CONNECT THE DIAGNOSTIC TOOL
(MUT-III)
Required Special Tools:
MB991958: DIAGNOSTIC TOOL (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A DTC CODE TROUBLE CONTENT
001 or U1700 Malfunction of SWS communication line or ETACS-ECU
002 or U1701 Malfunction of column switch
003 or U1702 Malfunction of front-ECU
004
*1 or U1073Malfunction of sunroof-ECU
010
*2 or U1073Bus Off
011 or U1100 Engine ECU time-out
012 or U1101 A/T ECU time-out
013 or U1110 A/C-ECU time-out
014 or U1108 Combination meter time-out
015
*3 or U1111Multi center display unit time-out
021 or U1128 Failure information on combination meter
CENTRALISED JUNCTION
CIRCUIT DIAGRAMS90-13
19 Front-ECU (Field
effect transistor for
headlamp: Low)Fuse 10 Red Headlamp (LH) and headlamp (Low:
LH)
20 Front-ECU (Taillamp
relay)7.5 Brown A/C-ECU, A/T selector lever position
illumination lamp, combination meter,
fog lamp switch, headlamp (RH),
glove box lamp, hazard warning lamp
switch, multi-center display unit,
radio, CD player, rear combination
lamp (RH), rheostat and TCL switch
21 7.5 Brown Headlamp (LH), license plate lamp
and rear combination lamp (LH)
22 Battery/Alternator
(Fusible link No.27)15 Blue A/C-ECU, column switch,
combination meter, ETACS-ECU,
front-ECU, key reminder switch, multi-
center display unit, radio, CD player,
and vanity mirror lamp
23 Ignition switch (ACC) 10 Red A/C-ECU, accessory socket relay,
ETACS-ECU, multi-center display
unit, radio, CD player.
24 Battery/Alternator
(Fusible link No.27)15 Blue Fuel pump module
25 Ignition switch (ACC) 30 Green Front-ECU and windshield wiper
motor
26 Battery/Alternator
(Fusible link No.27)Fusible
link20 Light blue Anti-lock braking system(solenoid
valve)
27
Alternator120
Battery, front-ECU, fusible link Nos.1,
2, 3, 4, 5 and 26 and fuse Nos.6, 7, 8,
9, 10, 11, 13, 14, 15, 22 and 24 (in
relay box) NO. POWER SUPPLY
CIRCUITNAME RATED
CAPACITY (A)HOUSING
COLOURLOAD CIRCUIT
