Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 676

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-31

DTC SET CONDITIONS

•

These DTC are output if the voltage between the
IG1 terminals (fuse No.13 or No.5 circuit) and
ground is lower than a predetermined value for a
continuous period of five second or more.
However, if the vehicle condition returns to
normal, DTC numbers 41 or 42 will be
automatically erased, and the SRS warning light
will switch off.

TROUBLESHOOTING HINTS

•

Damaged wiring harnesses or connectors

•

Malfunction of the SRS-ECU

DIAGNOSIS

STEP 1. Check the ignition switch (IG1) line at the SRS-
ECU connector C-72 by backprobing.
(1) Do disconnect the connector C-72.
(2) Connect the negative battery terminal.
(3) Turn the ignition switch to "ON" position.
(4) Measure the voltage between terminal 12 (for DTC 41) or 9

(for DTC 42) and the ground by backprobing.

•

Voltage should be 9 volts or more

Q: Is the voltage 9 volts or more?

YES : Go to Step 3.
NO : Go to Step 2.

STEP 2. Check the harness wires between the ignition
switch (IG1) and SRS-ECU connector C-72.
NOTE: After inspecting intermediate connectors C-101 and C-
107, inspect the wiring harness. If intermediate connectors are
damaged, repair or replace them. Refer to GROUP 00E,
Harness Connector Inspection

P.00E-2

. Then go to Step 5.

Q: Are harness wires between the ignition switch (IG1) and

SRS-ECU connector C-72 in good condition?
YES : Go to Step 5.
NO : Repair them. Then go to Step 5.

AC000367AC

C-72 CONNECTOR HARNESS SIDE VIEW

AC000358AD

SRS-ECU

ACCELERATOR PEDAL

CENTER REINFORCEMENT(LH)

CONNECTOR: C-72

AC000366AC

CONNECTOR: C-101, C-107

C-101

C-107

JUNCTION
BLOCK
(FRONT VIEW)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-32

STEP 3. Check the ground line at the SRS-ECU connector
C-72 by backprobing.
(1) Do disconnect the connector C-72.
(2) Measure the resistance between terminal 3 and ground by

backprobing.

Q: Is the resistance between terminal 3 and ground less

than 2 ohm?
YES : Replace the SRS-ECU. Refer to

P.52B-66

. Then go

to Step 5.

NO : Go to Step 4.

STEP 4. Check the harness wires between SRS-ECU
connector C-72 and ground.
Q: Are the harness wires between SRS-ECU connector C-

72 and ground in good condition?
YES : Go to Step 5.
NO : Repair them. Then go to Step 5.

STEP 5. Check for DTC.

Q: Is any of DTC 41 or 42 output?

YES : Replace the SRS-ECU. Refer to

P.52B-66

.

NO : This diagnosis is compleate.(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

P.00-6

.)

AC000368AC

C-72 CONNECTOR HARNESS SIDE VIEW

AC000358AD

SRS-ECU

ACCELERATOR PEDAL

CENTER REINFORCEMENT(LH)

CONNECTOR: C-72

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-33

DTC 43: SRS warning light drive circuit system fault 1 (Light does not illuminate.)/SRS warning light
drive circuit system fault 1 (Light does not switch off.)
DTC 44: SRS warning light drive circuit system fault 2

AC003884AB

SRS Warning Light Drive Circuit

AC000370AC

CONNECTOR: C-41, C-42

C-42

C-41

COMBINATION METER

AC000371AC

CONNECTORS: C-101, C-104

C-301

C-308

JUNCTION
BLOCK
(FRONT VIEW)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-34

CIRCUIT OPERATION

•

Power for the SRS warning light is supplied from
the ignition switch (IG1) circuit.

•

The SRS warning light illuminates when the
ignition switch is turned "ON" and goes out after
approximately 7 seconds if there is not a
malfunction in the SRS system.

•

The SRS-ECU judges how severe a collision is
by detecting signals from the left and right side
impact sensors 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 when an open circuit is
detected for a continuous period of five seconds
while the SRS-ECU is monitoring the SRS
warning light and the light is OFF. (transistor
OFF.) However, if the vehicle condition returns to
normal, DTC 43 will be automatically erased, and
the SRS warning light will go out.

•

This DTC is output when a short to ground occurs
in the harness between the SRS warning light
and SRS-ECU while SRS-ECU is monitoring the
light and the light is ON.

•

This DTC is output under one of the following
cases while the SRS-ECU is monitoring the
warning light drive circuit:

•

When a short circuit occurs in the warning
light drive circuit.

•

When a malfunction is detected in the output
transistor inside the SRS-ECU.

However, if the vehicle returns to normal condition,
DTC 44 will be automatically erased, and the SRS
warning light will go out.

TROUBLESHOOTING HINTS

•

Damaged wiring harnesses of connectors

•

Blown bulb (for DTC 43)

•

Malfunction of the SRS-ECU

•

Malfunction of the combination meter (for DTC
43)

DIAGNOSIS

STEP 1. Check the SRS warning light line at SRS-ECU
connector C-72 by backprobing.
(1) Do disconnect the connector C-72.
(2) Connect the negative battery cable.
(3) Turn the ignition switch to "ON" position.
(4) Connect terminal 4 to ground by backprobing.

•

The SRS warning light should illuminate.

Q: Does the SRS warning light illuminate?

YES : Replace the SRS-ECU. Refer to

P.52B-66

. Then go

to Step 6.

NO : Go to Step 2.

AC000358AD

SRS-ECU

ACCELERATOR PEDAL

CENTER REINFORCEMENT(LH)

CONNECTOR: C-72

AC000372AC

C-72 CONNECTOR HARNESS SIDE VIEW