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Mitsubishi Lancer Evolution 8. Manual - part 115

SRS AIRBAGS – TROUBLESHOOTING

52B-25

Check connectors: C-116,
C-124, D-02

Check the fault symptoms

Replace the SRS-ECU

Check harness between
the driver’s seat belt pre-
tensioner & SRS-ECU

Replace the driver’s seat belt pre-tensioner

Replace the
SRS-ECU

(Checking the circuit between the SRS-ECU
and the driver’s seat belt pre-tensioner)
Measure at the SRS-ECU connector C-124
• Detach the SRS-ECU connector C-124
• Detach the driver’s seat belt pre-tensioner

connector D-02 (see p.52B-34)

• Ignition switch ON
• Measure at harness side
• Voltage between 29, 30 and body earth

Caution
Do not insert the probe, etc. directly into
the terminal from the front side of the
connector, as this may cause a reduction
in contact pressure.

OK: 0V

connector D-02 (see p.52B-34)

• Measure at harness side
• Voltage between 29, 30 and body earth

Caution
Do not insert the probe, etc. directly into
the terminal from the front side of the
connector, as this may cause a reduction
in contact pressure.

OK: No connectivity

Code No. 66 Driver's seat belt pre-tensioner (squib) system (shorted to
power supply)

Code No. 67 Driver's seat belt pre-tensioner (squib) system (shorted to
earth)

Possible cause

This code is output when the driver's seat belt pre-tensioner (squib) circuit of
the SRS-ECU is shorted to the power supply (Code No. 66) or shorted to earth
(Code No. 67).

• Harness or connector fault
• Shorting of driver's seat belt pre-tensioner

(squib) harness to power supply (Code No.
66) or to earth (Code No. 67)

• SRS-ECU fault

(Checking the driver’s seat belt pre-tensioner (squib))
MUT-II/III diagnosis code
• Connect the dummy resistor (MB991865) to the resistor

harness (MB 991884)

• Detach the driver’s seat belt pre-tensioner connector D-02

(see p.52B-34)

• Connect the resistor harness (MB991884) to the harness

side of the driver’s seat belt pre-tensioner connector D-02

• Connect the (–) terminal of the battery
• After erasing the diagnosis code memory, reconfirm the

diagnosis code.

Is Code No. 66 or 67 output?

Dummy resistor
(MB991865)
Resistance (3

Ω

)

Resistor harness
(MB991884)

D-02 Driver’s seat belt pre-tensioner
connector (harness side)

C-124 connector

Y1740AU

Y1741AU

Repair

YES (No.66 output)

YES (No.67 output)

SRS AIRBAGS – TROUBLESHOOTING

52B-26

(Checking the circuit between the SRS-ECU
and the front passenger’s seat belt pre-
tensioner)
Measure at the SRS-ECU connector C-124
• Detach the SRS-ECU connector C-124
• Detach the front passenger’s seat belt pre-

tensioner connector D-14 (see p.52B-34)

• Ignition switch ON
• Measure at harness side
• Voltage between 27, 28 and body earth
Caution
Do not insert the probe, etc. directly into
the terminal from the front side of the
connector, as this may cause a reduction
in contact pressure.
OK: 0V

tensioner connector D-14 (see p.52B-34)

• Measure at harness side
• Voltage between 29, 30 and body earth
Caution
Do not insert the probe, etc. directly into
the terminal from the front side of the
connector, as this may cause a reduction
in contact pressure.
OK: No connectivity

Replace the front passenger’s seat belt pre-tensioner

Replace the SRS-ECU

Check connectors: C-116, C-
124, D-14

Check the fault symptoms

Replace the
SRS-ECU

Check harness between the
front passenger’s seat belt
pre-tensioner & SRS-ECU

Code No. 68 Front passenger's seat belt pre-tensioner (squib)
system (shorted to power supply)

Code No. 69 Front passenger's seat belt pre-tensioner (squib)
system (shorted to earth)

Possible cause

This code is output when the front passenger's seat belt pre-
tensioner (squib) circuit of the SRS-ECU is shorted to the power
supply (Code No. 68) or shorted to earth (Code No. 69).

• Harness or connector fault
• Shorting of front passenger's seat belt pre-tensioner

(squib) harness to power supply (Code No. 68) or to
earth (Code No. 69)

• SRS-ECU fault

(Checking the front passenger’s seat belt pre-tensioner
(squib))
MUT-II/III diagnosis code
• Connect the dummy resistor (MB991865) to the resistor

harness (MB 991884)

• Detach the front passenger’s seat belt pre-tensioner

connector D-14 (see p.52B-34)

• Connect the resistor harness (MB991884) to the harness

side of the front passenger’s seat belt pre-tensioner
connector D-14

• Connect the (–) terminal of the battery
• After erasing the diagnosis code memory, reconfirm the

diagnosis code.

Is Code No. 68 or 69 output?

Dummy resistor
(MB991865)
Resistance (3Ω)

Resistor harness
(MB991884)

D-14 Front passenger’s seat belt pre-
tensioner connector (harness side)

C-124 connector

Y1742AU

Y1743AU

YES (No.68 output)

YES (No.69 output)

Repair

SRS AIRBAGS – TROUBLESHOOTING

52B-27

6. Trouble Symptoms Category Chart

7. Trouble Symptoms Inspection Procedures

Inspection Procedure 1

Can the MUT-II/III communicate with other systems?

Inspect MUT-II diagnosis circuit, and repair

Check connectors: C-125, C-110, C-122

Inspect the harness between the SRS-ECU and the
diagnosis connector, and repair

Check connector: C-125

Inspect the harness between the SRS-ECU & earth, and repair

Check connectors: C-125, C-212, C-210

Inspect the harness between the SRS-ECU and the ignition
switch, and repair

Confirm the trouble symptoms

Measure at the SRS-ECU connector C-125 and the
diagnosis connector C-122

• Detach the SRS-ECU connector C-125 & the diagnosis

connector C-122, and measure at the harness side

• Connectivity between the following terminals

C-125 connector side

C-122 connector side

OK: No connectivity

Measure at the SRS-ECU connector C-125
• Detach the connector and measure at the harness side
(1) Connectivity between 7 & body earth

OK: Connectivity

• Connect the (-) terminal of the battery
• Ignition switch : ON
(2) Voltage between 13 & body earth

OK: 9 V or above

(3) Voltage between 16 & body earth

OK: 9 V or above

Replace the SRS-ECU

Symptom

Symptom Inspection Procedure No.

Reference page

Cannot communicate with MUT-II/III

52B-27

Cannot communicate with MUT-II/III

Possible cause

If there is no communication with any other parts of the system, then there is a
high probability that the diagnosis circuit is malfunctioning. If communication is
only possible with the SRS airbags, then it may be that there is a disconnection
in the SRS-ECU diagnosis output circuit or power supply circuit (including earth
circuit).

• Harness or connector fault
• SRS-ECU fault
• Incompatible MUT ROM pack

YES

Repair

(1) NG

(2), (3)
NG

SRS AIRBAGS – POST-COLLISION DIAGNOSIS

52B-28

Post-Collision Diagnosis

The following procedure must be used to check and service the vehicle after a collision, regardless of whether or not the
airbags have been deployed. Apart from the items listed below, servicing is the same as that for the previous model.

1. Repair procedure

1-1 When the SRS airbags have deployed

(1) Replace the front impact sensors with new sensors. (See p.52B-30)
(2) Check for pinching of the harness, damage to the connectors and deformation of the terminals.

1-2 When the airbags have not deployed, in a low-speed collision

(1) Inspect the front impact sensors.
(2) If a visual inspection of the front impact sensors reveals any dents, fractures, deformation, or the like, then the sensors

must be replaced with new ones.

(3) For information on removing and reinstalling front impact sensors, see “Servicing SRS airbag and seat belt pre-tensioner

components” (p.52B-29–31).

Front impact sensors

(1) Check for any deformation or corrosion of the headlight support

panel

(2) Check for any dents, fractures or deformations in the front

impact sensors.

(3) Check for any pinching of the centre harness, damage to the

connectors, or deformation of the terminals.

Radiator

Front impact sensor

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