Buick Regal: Head-Up Display Malfunction
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
Diagnostic Fault Information
1. Head-Up Display Malfunction
Circuit/System Description
The head-up display projects a full color image onto the windshield and is
only viewable from the driver
seat. The image location and brightness is adjustable using the head-up display
switch. The image
information is received from the instrument cluster through a video cable.
The head-up display is a slave device to the instrument cluster. The head-up
display is powered through
ignition voltage and ground. It communicates directly with instrument cluster
via serial data and only
has limited self-diagnosis capacity. Head-up display DTCs are reported through
the Instrument Cluster.
The head-up display switch is a multiplexed switch that controls the head-up
display based on driver
inputs. The head-up display provides the switch with a low reference and
monitors a signal circuit. The
head-up display switch is made up of a resistor ladder and three switches: Dim
+/-, Up/Down, and Page.
When a switch is pressed, the signal voltage is pulled low through the resistor
ladder. When pressed,
each of the switches will result in a different signal voltage seen by the
head-up display, depending on
the switch's location on the resistor ladder.
Reference Information
Schematic Reference
Head-Up Display Wiring Schematics
Steering Wheel Secondary/Configurable Control Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEW INDEX
Description and Operation
Instrument Cluster Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Verification
1. Ignition ON.
2. While holding each switch listed below, verify the scan tool Head-Up Display
Switch parameter is
as follows:
- DIM + Switch - HUD Dimming Up/Down Pressed
- DIM - Switch - HUD Dimming Up/Down Pressed
- UP Switch - HUD Movement
- DOWN Switch - HUD Movement
- PAGE Switch - HUD Page Switch
- If the scan tool parameter does not equal the expected result with
the switch in the
appropriate state
Refer to Inoperative Head-Up Display Switch Circuit/System Testing.
- Go to next step: If the scan tool parameter equals the expected
result with the switch
in the appropriate state
3. Verify the P29 Head-Up Display performs the following function with the
switch in the
appropriate state:
- DIM + Switch - Head-up display brightness increases
- DIM - Switch - Head-up display brightness decreases
- UP Switch - Head-up display image moves up
- DOWN Switch - Head-up display image moves down
- PAGE Switch - Head-up display image changes pages
- If the P29 Head-Up Display does not perform the expected function
with the switch in
the appropriate state
Refer to Inoperative Head-Up display Circuit/System Testing.
- Go to next step: If the P29 Head-Up Display performs the expected
function with the
switch in the appropriate state
4. All OK.
Circuit/System Testing
NOTE: Circuit/System Verification must be performed before proceeding
with
Circuit/System Testing.
Inoperative Head-Up Display
1. Ignition OFF, disconnect the harness connector at the P29 Head-Up Display,
ignition ON.
2. Test for 2 - 10 V between the S70R Steering Wheel Controls Switch - Right
serial data circuit
terminal 7 and ground.
- Ignition OFF, disconnect the harness connector at the P16 Instrument
Cluster.
- Test for infinite resistance between the S70R Steering Wheel Controls
Switch - Right serial
data circuit terminal 7 and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for infinite resistance between the P29 Head-Up Display serial data
circuit terminal 1
and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the S70R Steering Wheel Controls Switch -
Right serial data circuit
end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the P16 Instrument Cluster.
- Ignition OFF, disconnect the harness connector at the P16 Instrument
Cluster, ignition ON.
- Test for less than 1 V between the S70R Steering Wheel Controls Switch -
Right serial data
circuit terminal 7 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V.
- Test for less than 1 V between the P29 Head-Up Display serial data
circuit terminal 1 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the P16 Instrument Cluster.
- Go to next step: If between 2 - 10 V
3. Connect the harness connector at the S70R Steering Wheel Controls Switch -
Right. Ignition ON.
4. Verify steering wheel controls function properly.
- If steering wheel controls function properly
Replace P29 Head-Up Display.
- Go to next step: If steering wheel controls do not function properly
5. Ignition OFF. Disconnect harness connector at the S70R Steering Wheel
Controls Switch - Right.
Connect the harness connector at the and P29 Head-Up Display. Ignition ON.
6. Verify head-up display functions properly.
- If head-up display functions properly
Replace S70R Steering Wheel Controls Switch - Right.
- Go to next step: If head-up display does not function properly
7. Replace the video cable between the P29 Head-Up Display and the P16
Instrument Cluster.
Ignition ON.
8. Verify head-up display functions properly.
- If head-up display functions properly
All OK.
- Go to next step: If head-up display does not function properly
9. Replace P16 Instrument Cluster.
Inoperative Head-Up Display Switch
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector
at the S27 Head-Up
Display Switch. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the low reference circuit terminal 3 and
ground.
- Ignition OFF, disconnect the harness connector at the P29 Head-Up
Display.
- Test for less than 2 Ω in the low reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the P29 Head-Up Display.
- Go to next step: If less than 10 Ω
3. Ignition ON.
4. Test for 4.8 - 5.2 V between the signal circuit terminal 4 and ground.
- Ignition OFF, disconnect the harness connector at the P29 Head-Up
Display.
- Test for infinite resistance between the signal circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance.
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the P29 Head-Up Display.
- Ignition OFF, disconnect the harness connector at the P29 Head-Up
Display, ignition ON.
- 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.
- If less than 1 V, replace the P29 Head-Up Display.
- Go to next step: If between 4.8 - 5.2 V
5. Test or replace the S27 Head-Up Display Switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S27 Head-Up Display
Switch.
2. Test for 3.4K - 4.2K Ω between the signal terminal 4 and the low reference
terminal 3.
- If not between 3.4K - 4.2K Ω
Replace the S27 Head-Up Display Switch.
- Go to next step: If between 3.4K - 4.2K Ω
3. Test for 87 - 107 Ω between the signal terminal 4 and the low reference
terminal 3 with the Dim +
switch pressed.
- If not between 87 - 107 Ω
Replace the S27 Head-Up Display Switch.
- Go to next step: If between 87 - 107 Ω
4. Test for 291 - 356 Ω between the signal terminal 4 and the low reference
terminal 3 with the Dim -
switch pressed.
- If not between 291 - 356 Ω
Replace the S27 Head-Up Display Switch.
- Go to next step: If between 291 - 356 Ω
5. Test for 575 - 704 Ω between the signal terminal 4 and the low reference
terminal 3 with the Up
switch pressed.
- If not between 575 - 704 Ω
Replace the S27 Head-Up Display Switch.
- Go to next step: If between 575 - 704 Ω
6. Test for 1K - 1.2K Ω between the signal terminal 4 and the low reference
terminal 3 with the
Down switch pressed.
- If not between 1K - 1.2K Ω
Replace the S27 Head-Up Display Switch.
- Go to next step: If between 1K - 1.2K Ω
7. Test for 1.7K - 2.1K Ω between the signal terminal 4 and the low reference
terminal 3 with the
Page switch pressed.
- If not between 1.7K - 2.1K Ω
Replace the S27 Head-Up Display Switch.
- Go to next step: If between 1.7K - 2.1K Ω
8. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Displays and Gauges Component Replacement Reference
- Control Module References for control module replacement, programming,
and setup
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Diagnostic
System Check - Vehicle
Review the description of Strategy Based Diagnosis:Strateg
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
SEE MORE:
If equipped, the liftgate may be
operated with a kicking motion
under the projected logo. The RKE
transmitter must be within 1 m (3 ft).
The hands-free feature will not work
while the liftgate is moving. To stop
the liftgate while in motion use one
of the liftgate switches.
The hands-free feature
WIPER/WASHER SYSTEM DESCRIPTION AND OPERATION
Wiper/Washer System Components
The wiper/washer system consists of the following electrical components:
Windshield Wiper Relay
Windshield Wiper Speed Control Relay
Windshield Washer Pump
Windshield Washer Pump Relay
Windshield Wiper Motor
Windshie