Seat Belt Indicator Malfunction - Passenger
Diagnostic Instructions
Diagnostic Fault Information
Circuit
|
Short to Ground
|
High Resistance
|
Open
|
Short to Voltage
|
Signal Performance
|
Passenger Seat Belt Switch Signal
|
1
|
2
|
2
|
2
|
-
|
Passenger Seat Belt Switch Low Reference
|
-
|
2
|
2
|
2
|
-
|
1. Indicator will remain ON with seat belt buckled.
2. Indicator will illuminate only for the bulb check.
|
|
|
Circuit/System Description
When an individual is sitting in the passenger seat the
passenger presence sensor detects the individual. A signal to the
SDM indicates a person is in the passenger seat. The SDM will turn
the passenger seat belt indicator on. The passenger seat belt
switch is a 2-wire switch wired to the inflatable restraint sensing
and diagnostic module (SDM) using a signal circuit and a low
reference circuit. When the seat belt is unbuckled the switch is
closed, and when the seat belt is buckled the switch is open. The
SDM sends the status of the passenger seat belt via a hard wire to
the hazard warning switch. After receiving the message, the hazard
warning switch controls the illumination of the passenger seat belt
indicator.
Reference Information
Schematic Reference
Seat Belt Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Seat Belt System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
2. |
Have someone sit in the
passenger seat. |
3. |
With a scan tool verify the
Automatic Occupant Sensing Current Front Occupancy Status indicates
Occupied. |
⇒ If the Automatic
Occupant Sensing Current Front Occupancy Status does not indicate
Occupied
|
3.1 |
Disconnect the harness
connector at the K36 SDM. |
|
3.2 |
Test for infinite resistance
between the folowing circuits terminal and ground: |
|
|
- |
Sensor signal circuit terminal |
|
|
- |
Sensor low reference circuit terminal |
⇒ |
If less than infinite resistance, repair the short to ground on
the circuit. |
|
3.3 |
Test for less than 2 Ω
in each circuit end to end. |
⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
⇒ |
If less than 2 Ω, replace the passenger presence
sensor. |
⇓ If the Automatic
Occupant Sensing Current Front Occupancy Status does indicate
Occupied
5. |
With a scan tool perform the
Passenger Seat Belt Reminder Indicator On/Off Control Function and
verify the passenger seat belt indicator turns on and off.
|
⇒ If the passenger
seat belt indicator does not turn on and off
⇒ |
Refer to Seat Belt Inidicator Malfunction. |
⇓ If the passenger
seat belt indicator does turn on and off
6. |
With the scan tool monitor the
Passenger Seat Belt Status parameter while buckling and unbuckling
the seat belt. The parameter should display Buckled and Unbuckled
when buckling and unbuckling the seat belt. |
⇒ If the Passenger
Seat Belt Status parameter does not display Buckled and
Unbuckled
⇒ |
Refer to Seat Belt Switch Malfunction. |
⇓ If the Passenger
Seat Belt Status parameter does display Buckled and
Unbuckled
7. |
Replace the passenger presence
sensor. |
Circuit/System Testing
Seat Belt Switch Malfunction
2. |
Disconnect the harness
connector at the appropriate B88 passenger seat belt switch.
|
3. |
Test for less than 5 Ω
between the ground circuit terminal 2 and ground. |
⇒ If 5 Ω or
greater
|
3.1 |
Disconnect the harness
connector at the K36 SDM. |
|
3.2 |
Test for less than 2 Ω
in each control circuit end to end. |
⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
⇒ |
If less than 2 Ω, replace the K36 SDM. |
5. |
Verify the scan tool Passenger
Seat Belt Status parameter listed below is Buckled. |
⇒ If the scan tool
Passenger Seat Belt Status parameter does not display
Buckled
|
5.1 |
Disconnect the harness
connector at the K36 SDM. |
|
5.2 |
Test for infinite resistance
between the seat belt switch signal circuit terminal 2 and
ground. |
⇒ |
If less than infinite resistance, repair the short to ground on
the circuit. |
⇒ |
If less than 2 Ω, replace the K36 SDM. |
⇓ If the scan tool
Passenger Seat Belt Status parameter does display
Buckled
6. |
Install a 3 A fused jumper
wire between the signal circuit terminal 1 and the ground circuit
terminal 2. |
7. |
Verify the scan tool Passenger
Seat Belt Status parameter is Unbuckled. |
⇒ If the scan tool
Passenger Seat Belt Status parameter does not display
Unbuckled
|
7.1 |
Disconnect the harness
connector at the K36 SDM. |
|
7.3 |
Test for less than 1 V between
the signal circuit and ground. |
⇒ |
If 1 V or greater, repair the short to voltage on the
circuit. |
|
7.4 |
Test for less than 2 Ω
in each circuit end to end. |
⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
⇒ |
If less than 2 Ω, replace the K36 SDM. |
⇓ If the scan tool
Passenger Seat Belt Status parameter does display
Unbuckled
8. |
Replace the B88 passenger seat
belt switch. |
Seat Belt Indicator Malfunction
2. |
Disconnect the harness
connector at the S26 hazard warning switch. |
3. |
Test for less than 5 Ω
between the ground circuit terminal 1 and ground. |
⇒ If 5 Ω or
greater
|
3.1 |
Disconnect the harness
connector at the K36 SDM. |
|
3.2 |
Test for less than 2 Ω
in each control circuit end to end. |
⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
⇒ |
If less than 2 Ω, replace the K36 SDM. |
4. |
Connect a test lamp between
the control circuit terminal 4 and ground. |
6. |
Command the Passenger Seat
Belt Reminder ON and OFF with a scan tool, the test lamp should
turn ON and OFF while changing between the commanded states.
|
⇒ If the test lamp
is always on
|
6.2 |
Disconnect the harness
connector at the K36 SDM. |
|
6.4 |
Test for less than 1 V between
the signal circuit and ground. |
⇒ |
If 1V or greater, repair the short to voltage on the
circuit. |
⇒ |
If less than 1V, replace the K36 SDM. |
⇒ If the test lamp
is always off
|
6.1 |
Disconnect the harness
connector at the K36 SDM. |
|
6.2 |
Test for infinite resistance
between the seat belt switch signal circuit terminal 4 and
ground. |
⇒ |
If less than infinite resistance, repair the short to ground on
the circuit. |
|
6.3 |
Test for less than 2 Ω
in each control circuit end to end. |
⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
⇒ |
If less than 2 Ω, replace the K36 SDM. |
⇓ If test lamp turns
on and off while changing between the commanded
states
7. |
Replace the S26 hazard warning
switch. |
Component Testing
2. |
Disconnect the harness
connector at the appropriate B88 passenger seat belt switch.
|
3. |
B88 seat belt buckle in the
open position. |
4. |
Test for infinite resistance
between the signal circuit terminal 1 and the ground terminal 2 at
the B88 passenger seat belt switch. |
⇒ If there is not
infinite resistance
⇒ |
Replace the B88 passenger seat belt switch. |
⇓ If there is
infinite resistance
5. |
B88 seat belt switch in the
closed position. |
6. |
Test for less than 2 Ω
between the signal circuit terminal 1 and the ground terminal 2 at
the B88 passenger seat belt switch. |
⇒ If 2 Ω or
greater
⇒ |
Replace the B88 passenger seat belt switch. |
⇓ If less than 2
Ω
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|