Mitsubishi Montero (2004+). Manual - part 1184

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-71

DTC 28: Passenger’s (Front) Seat Belt Pre-Tensioner (Squib) System Fault 1 (Short Circuit between 
Terminals of the Squib Circuit)

SEAT BELT
PRETENSIONER
(RH)

MICROCOMPUTER

AIR BAG DRIVE CIRCUIT

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR
  COUPLED: ON
  CONNECTOR
  UNCOUPLED: OFF

Passenger's (Front) Seat Belt Pre-tensioner (Squib)

ACX01478AI

CONNECTOR: E-07

E-07 (Y)

AC204603AD

CONNECTOR: E-16

FLOOR 
CONSOLE

E-16

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-72

.

CIRCUIT OPERATION
The side impact sensor includes an analog G sensor 
and CPU, etc. The CPU monitors the analog G sen-
sor output signal. If the CPU judges that the side-air-
bags should be deployed, it sends a fire signal to the 
SRS-ECU to deploy the side-airbags. Besides that, 
the CPU diagnoses the internal components of the 
side impact sensor. If a malfunction occurs, it 
requests the SRS-ECU to set a diagnostic trouble 
code.

.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance 
between the input terminals of the passenger’s seat 
belt pre-tensioner (squib).

.

TROUBLESHOOTING HITS

• Improper engaged connector or defective short 

spring*

• Short circuit between the passenger's seat belt 

pretensioner (squib) circuit terminals

• Damaged connector(s)

• Malfunction of the SRS-ECU

.

NOTE:  *: The squib circuit connectors integrate a 
"short" spring (which prevents the air bag from 
deploying unintentionally due to static electricity by 
shorting the positive wire to the ground wire in the 
squib circuit when the connectors are disconnected) 
(Refer to 

P.52B-3

). Therefore, if connector E-07 or 

F-29 is damaged or improperly engaged, the short 
spring may not be released when the connector is 
connected.

.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B (Vehicles without 

CAN communication system)

• MB991865: Dummy resister

• MB991866: Resister harness

AC204127

AB

CONNECTOR: F-29

F-29 (R)

CENTER 
PILLAR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-73

STEP 1. Check the diagnostic trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOOK (OFF)" position.
Q: Is DTC 34 set?

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

STEP 2. Check the SRS-ECU connector E-07.
Q: Is connector correctly engaged?

YES : Go to Step 3.
NO :  Engage the connector to the place. Then go to Step 7.

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

ACX01478AJ

CONNECTOR: E-07

E-07 (Y)

34 35 36 37 38 39 40 41 42

25 26 27 28 29 30 31 32 33

21 22

23 24

HARNESS SIDE
CONNECTOR
(REAR VIEW)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-74

STEP 3. Check SRS-ECU connector E-07 and passenger’s 
seat belt pre-tensioner connector F-29. (Using scan tool 
MB991958, read the diagnostic trouble code).
(1) Disconnect the negative battery terminal.
(2) Disconnection connectors E-07 and F-29, and then 

reconnect them.

(3) Connect the negative battery terminal.
(4) Erase the diagnostic trouble code memory, and the 

diagnostic trouble code.

Q: Is DTC 28 set?

YES : Go to Step 4.
NO :  The procedure is complete. It is assumed that DTC 28 

set as connector E-07 or F-29 was engaged 
improperly.

ACX01478AJ

CONNECTOR: E-07

E-07 (Y)

34 35 36 37 38 39 40 41 42

25 26 27 28 29 30 31 32 33

21 22

23 24

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC204127

AD

CONNECTOR: F-29

F-29 (R)

CENTER 
PILLAR

1 2

HARNESS SIDE
CONNECTOR
(REAR VIEW)