TCM FB30-7 - Page 56

3. CONTROL SYSTEM
- 44 -
(3) PS system
No.
50
[ 403]
51
[ 405]
52
[ 406]
53
[ 501]
54
[ 503]
56
[ 404]
Problem
PS main Tr. shorted
PScontactor(MPS)
shorted
Detection circuit harness
defective
PScontactor(MPS)
stuck open.
PS main fuse (F3) stuck
open
Detection circuit harness
defective
PScontactor(MPS)coil
drive Tr. defective
(Tr5 inside CPU board)
Detection circuit harness
defective
PS torque sensor output
defective
PS main Tr. stuck open.
Drive circuit harness
defective
EPS board defective
PS motor stuck open.
Error
Hard steering wheel (PS
does not work)
(MPScontactordoesnot
close.)
Normal operation (The
error code remains
displayed.)
Hard steering wheel (PS
does not work.)
(MPScontactordoesnot
close.)
Hard steering wheel (PS
does not work.)
Hard steering wheel (PS
does not work.)
Hard steering wheel (PS
does not work.)
Remedy
Proceed with remedy in numerical order of encircled numbers.
① CheckmainTr.(TMPS1,2)andchangeifneeded.
 (WhenchangingeitheroftheTMPS1or2,
change the other one, too, along with EPS board.)
② Check harness between CN4-1 (CPU board) and
P22 terminal, and repair or change if needed.
③ Check harness between CN4-8 (CPU board) and
P1 terminal, and repair or change if needed.
④ If no defect is found throughout the above steps,
change PS board.
① CheckPScontactor(MPS),andrepairifneeded.
② Check harness between CN4-9 (CPU board) and
P21 terminal, and repair or change if needed.
③ Check CN4-1 (CPU board) and P22 terminal,
and repair or change if needed.
① CheckPScontactor(MPS),andrepairorchange
if needed.
(foreign matter between contact points,
mechanical hitch)
② Check harness between CN4-9 (CPU board) and
P21 terminal, and repair or change if needed.
③ Check harness between CN4-1 (CPU board) and
P22 terminal, and repair or change if needed.
④ Check PS main fuse (F3) and change if needed.
⑤ Check harness between CN4-9 (CPU board) and
P21 terminal, and repair or change if needed.
⑥ Check harness between CN4-8 (CPU board) and
P1 terminal, and repair or change if needed.
① CheckPScontactor(MPS)coilconnectorsfor
disconnection and coil for broken wire, and
repair or change if needed.
② Check harness between contactor coil connector
and CN4-6, 14 (CPU board), and repair or
change if needed.
③ Change CPU board (drive Tr defective)
① Check connectors and harnesses between torque
sensor and CN2-6, 7, 18 (CPU board), and repair
if needed.
② Check PS torque sensor, and repair or change if
needed.
① Check PS motor and wiring for opening, and
repair or change if needed.
(Pay attention to poor connection of brushes, too.)
② Check connectors and harnesses between G and
EterminalsofmainTr.(TMPS1,2)andCN8R
(power supply board) for breakage or shorting,
and repair or change if needed.
③ Check connector and harness between CN6R
(power supply board) and CN2E (EPS board),
and repair or change if needed.
④ Check connector and harness between CN6 (CPU
board) and CN1E (EPS board), and repair or
change if needed.
⑤ CheckmainTr(TMPS1and2),andchangeif
needed.
 (WhenchangingeitheroftheTMPS1and2,
change the other one, too, along with the EPS
board.)
⑥ If any defect is not found throughout the above
steps, change PS board.
Reset
Turn off
key switch.
Turn off
key switch.
Turn off
key switch.
Turn off
key switch.
Turn off
key switch.
Remarks
Check for secondary-side
voltage of fuse (F3)
Torque sensor power
supply voltage under
normal condition:
4.6 V (between CN2-7
and 18)
Torque sensor output
voltage when the error is
detected:
less than 0.1 V and more
than 4.6 V (between
CN2-6 and N terminal)
Numbers in brackets are error codes that appear on the meter panel.