Mitsubishi Galant. Manual — part 602

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM(SRS)

52B-49

CIRCUIT OPERATION

•

The SRS-ECU judges how severe a collision is
by detecting signals from the side impact sensor
and the analog G-sensor. If the impact is over a
predetermined level, the SRS-ECU outputs an
ignition signal. At this time, if the safing G-sensor
is on, the SRS air bag will inflate.

DTC SET CONDITIONS

•

This DTC is output if a poor connection at the
SRS-ECU is detected. However, if the vehicle
condition returns to normal, DTC number 34 will
be automatically erased, and the SRS warning
light will go out.

TROUBLESHOOTING HINTS

•

Damaged connectors

•

Malfunction of the side air bag module (LH)
(squib)

•

Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:

•

MB991502: Scan Tool (MUT-II)

•

MB991223 (MB991222): Harness set (Probe)

STEP 1. Check the side impact sensor (LH) line at the SRS-
ECU connector C-45 by backprobing.
(1)Do disconnect the side impact sensor (LH) connector D-20.
(2)Connect the negative battery terminal.
(3)Turn the ignition switch to "ON" position.
(4)Measure the voltage between terminal 1 and the ground by

backprobing.

•

Voltage should be 9 volts or more

(5)Check the continuity between terminal 3 and the ground by

backprobing.

•

Should be less than 2 ohm.

Q: Does the voltage meet the specifications or is the

resistance less than 2 ohm?
YES : Replace the side impact sensor (LH). Refer to

P.52B-

67

. Then go to Step 3.

NO : Go to Step 2.

AC003696AB

D-20 CONNECTOR
HARNESS SIDE VIEW

AC003697AB

D-20 CONNECTOR
HARNESS SIDE VIEW

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM(SRS)

52B-50

STEP 2. Check the harness wires between SRS-ECU
connector C-45 and side impact sensor (LH) connector D-
20.
NOTE: After inspecting intermediate connector D-23, inspect
the wiring harness. If the intermediate connector D-23 is
damaged, repair or replace it. Refer to GROUP 00E, Harness
Connector Inspection

P.00E-2

. Then go to Step 3. If harness

wires are in good condition, go to Step 3. If any harness wires
between SRS-ECU connector C-45 and side impact sensor
(LH) connector D-20 are damaged, repair them or install the
sensor cable. Refer to

P.52B-74

. Then go to Step 3.

Q: Are the harness wires between SRS-ECU connector C-

45 and side impact sensor (LH) connector D-20 in good
condition?
YES : Go to Step 3.
NO : Repair them. Then go to Step 3.

STEP 3. Check DTC.

Q: Is DTC 91output?

YES : Replace the SRS-ECU. Refer to

P.52B-65

.

NO : This diagnosis is complete.(If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction.)

DTC 92: Left hand side-impact sensor system for fault 1
DTC 95: Right hand side-impact sensor system for fault 1

DTC SET CONDITIONS

•

This DTC is output if the following are detected

from the analog G-sensor output.

•

Analog G-sensor is not operating.

AC003195AD

CONNECTOR: C-45

CENTER
REINFORCEMENT

SRS-ECU

AC003207AB

CONNECTOR: D-20

AC003208AB

CONNECTOR: D-23

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM(SRS)

52B-51

•

Analog G-sensor characteristics are
abnormal.

•

Analog G-sensor output is abnormal.

TROUBLESHOOTING HINTS

•

Malfunction of side impact sensor <LH> (for DTC
92) and side impact sensor <RH> (for DTC 95)

DIAGNOSIS
Replace side impact sensor <LH> (for DTC 92) and side impact
sensor <RH> (for DTC 95). Refer to

P.52B-74

.

Q: Is any of DTC 92 or 95 output?

YES : Replace the SRS-ECU. Refer to

P.52B-65

.

NO : This diagnosis is complete.(If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction.)

DTC 94: Right hand side-impact sensor power supply circuit system

AC000827AB

Side Impact Sensor (RH) Power Supply Circuit

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM(SRS)

52B-52

CIRCUIT OPERATION

•

The SRS-ECU judges how severe a collision is
by detecting signals from the side impact sensor
and the analog G-sensor. If the impact is over a
predetermined level, the SRS-ECU outputs an
ignition signal. At this time, if the safing G-sensor
is on, the SRS air bag will inflate.

DTC SET CONDITIONS

•

This DTC is output if the power supply voltage of
the side impact sensor (RH) drops below the
rated value for a continuous period of 5 seconds
or more. However, DTC number 94 will be
automatically cleared and the SRS warning light
will switch off if the condition returns to normal.

TROUBLESHOOTING HINTS

•

Damaged wiring harnesses or connectors

•

Malfunction of the side air bag module (RH)
(squib)

•

Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:
MB991502: Scan Tool (MUT-II)

AC003195AD

CONNECTOR: C-45

CENTER
REINFORCEMENT

SRS-ECU

AC003212AB

CONNECTOR: D-18

AC003211AB

CONNECTOR: D-09