Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 556

Code No.27 Driver's seat belt pre-tensioner (squib)
system
This code is output when open circuit occurs in the SRS-ECU driver's seat belt
pre-tensioner (squib) circuit.
However, SRS warning lamp goes out when a normal operation is resumed
(diagnosis code is not cleared.)
Dummy resistor
(MB991865)
resistance (3Ω)
Instrumental panel
wiring harness
<Check the circuit between the SRS-ECU and the driver's
seat belt pretensioner>
Measure at the SRS-ECU connector C-41, the driver's seat
belt pre-tensioner connector D-28*
D Disconnect the SRS-ECU connector C-41 , the driver's
seat belt pre-tensioner connector D-28*
then measure at the harness side.
D Continuity check between the following terminals
Connector C-41
29 –
30 –
Caution
Do not directly insert a probe or other devices at the
front of the connector to avoid a possible decrease in
the contact pressure.
OK: Continuity (2Ω or less)
D-28* D-26*
1 2
,
Connector C-41
Replace the SRS-ECU.
NOTE
*1: L.H. drive vehicles
*2: R.H. drive vehicles
SRS -
Resistor harness
(MB991866)
Driver's seat belt
pre-tensioner connector
YES
and D-26
1 *2
.
1 2
and D-26* , and
, 2
D-28* D-26*
1
2
1
connector
OK
Troubleshooting
Possible Cause
D Connector improper contact
D Open in the driver's seat pre-tensioner (squib)
circuit
D SRS-ECU inoperable
<Check the driver's seat belt pre-tensioner (squib)>
MUT-II self-diag code
D Connect the dummy harness (MB991865) to the resistor harness
(MB991866).
D Disconnect the driver's seat belt pre-tensioner connector D-28*
2
D-26* and insert the resistor harness (MB991866) behind the harness
side connector.
Caution
Do not directly insert a probe or other devices at the front of the
connector to avoid a possible decrease in the contact pressure.
D Connect the negative (- ) terminal of the battery
D Check the diagnosis code again after erasing the memory.
Is code No.27 output?
Replace the driver's seat belt pre-tensioner.
NG
Check connector: D-28
OK
Check the trouble
symptoms.
NG
Check the harness between the driver's seat belt pre-tensioner
and the SRS-ECU, and repair if necessary.
52B-25
1
NO
* * *
D-26 , C-133 , C-112 , C-124
1 2 1 2
* ,
NG
Correct
and