DTC B3650
Diagnostic Instructions
DTC Descriptor
| DTC B3650 08: High Beam Request Signal Circuit
Performance - Signal Invalid |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
High Beam Request Signal
|
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-
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B3650 08
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Circuit/System Description
When the low beam is activated and the turn signal/multifunction
switch is placed in the high beam position, the body control module
(BCM) will receive a ground signal through the turn
signal/multifunction switch signal circuit to illuminate the high
beam lamps.
Conditions for Running the DTC
Low beam is ON and high beam is activated.
Conditions for Setting the DTC
The body control module (BCM) reports stuck turn
signal/multifunction switch.
Action Taken When the DTC Sets
The BCM will not attempt to switch ON the high beam lamps.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, turn the headlamp switch in the low beam position.
Push/pull the turn signal/multifunction switch between the ON/OFF
position. The high beam lamps should be ON/OFF as the switch is
cycled.
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
S78 Turn Signal/Multifunction Switch harness connector.
|
| 2. |
Disconnect the negative
terminal of the C1 Battery. |
| 3. |
Test for less than 5 Ω
between the ground circuit terminal 3 and ground. |
| ⇒ |
If greater then the specified value, test the
ground circuit for an open/high resistance. |
| 4. |
Reconnect the negative
terminal to the C1 Battery. |
| 5. |
Connect the S78 Turn
Signal/Multifunction Switch harness connector. |
| 6. |
Disconnect the X3 harness
connector at the K9 Body Control Module. |
| 7. |
Connect a test lamp between B+
and the signal circuit terminal 11 X3. |
| 8. |
Push/pull the S78 Turn
Signal/Multifunction Switch between the high beam and OFF position.
The test lamp should turn ON and OFF as the switch is
cycled. |
| ⇒ |
If the test lamp is always OFF, test the signal
circuit for a short to voltage or an open/high resistance. If the
circuit test normal, replace the S78 Turn Signal/Multifunction
Switch. |
| ⇒ |
If the test lamp is always ON, test the signal
circuit for a short to ground. If the circuit test normal, replace
the S78 Turn Signal/Multifunction Switch. |
| 9. |
If all circuits test normal,
replace the K9 Body Control Module. |
Component Testing
Static Test
| 1. |
Ignition OFF, disconnect the
S78 Turn Signal/Multifunction Switch harness connector. S78 Turn
Signal/Multifunction Switch in flash position, test for less than 5
Ω between terminal 4 and terminal 3. |
| ⇒ |
If greater than the specified value, replace the
S78 Turn Signal/Multifunction Switch. |
| 2. |
S78 Turn Signal/Multifunction
Switch in high beam position, test for less than 5 Ω between
terminal 2 and terminal 3. |
| ⇒ |
If greater than the specified value, replace the
S78 Turn Signal/Multifunction Switch. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
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