FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Cadillac >> 2013 >> XTS AWD V6-3.6L >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Head Up Display Malfunction

Head Up Display Malfunction




Head-Up Display Malfunction
cell-id="">

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






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 Schematics Head-Up Display Schematics

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Instrument Cluster Description and Operation Instrument Cluster

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify a test pattern is displayed is displayed on the P29 head-up display when performing the Head-Up Display Pattern Check on the scan tool.

• If the test pattern is not displayed

1. Replace the video cable between the P29 Head-Up Display and the P16 Instrument Cluster.

2. Verify a test pattern is displayed is displayed on the P29 Head-Up Display when performing the Head-Up Display Pattern Check on the scan tool.

• If the test pattern is not displayed, replace the P16 Instrument Cluster.

• If the test pattern is displayed

3. All OK.

• If the test pattern is displayed

3. While holding each switch listed below, verify the scan tool Heads Up Display Switch State parameter is as follows:

* Dim + - HUD Dimming Up/Down Pressed

* Dim - - HUD Dimming Up/Down Pressed

* Up - HUD Movement

* Down - HUD Movement

* Page - HUD Page Switch

• If the scan tool parameter does not equal the expected result with the switch in the appropriate state
Refer to Circuit/System Testing.

• If the scan tool parameter equals the expected result with the switch in the appropriate state

4. Verify the P29 Head-Up Display performs the following function with the switch in the appropriate state:

* Dim + - Head-up display brightness increases

* Dim - - Head-up display brightness decreases

* Up - Head-up display image moves up

* Down - Head-up display image moves down

* Page - 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
Replace the P29 Head-Up Display.

• If the P29 Head-Up Display performs the expected function with the switch in the appropriate state

5. All OK.

Circuit/System Testing

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 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal 3 and ground.

• If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the P29 Head-Up Display.

2. Test for less than 2 ohms in the low reference circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the P29 Head-Up Display.

• If less than 10 ohms

3. Ignition ON.

4. Test for 4.8-5.2 V between the signal circuit terminal 4 and ground.

• If less than 4.8 V

1. Ignition OFF, disconnect the harness connector at the P29 Head-Up Display.

2. Test for infinite resistance between the signal circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance.

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the P29 Head-Up Display.

• If greater than 5.2 V

1. Ignition OFF, disconnect the harness connector at the P29 Head-Up Display, ignition ON.

2. 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.

• 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 ohms between the signal terminal 4 and the low reference terminal 3.

• If not between 3.4K - 4.2K ohms
Replace the S27 Head-Up Display Switch.

• If between 3.4K - 4.2K ohms

3. Test for 87 - 107 ohms between the signal terminal 4 and the low reference terminal 3 with the Dim + switch pressed.

• If not between 87 - 107 ohms
Replace the S27 Head-Up Display Switch.

• If between 87 - 107 ohms

4. Test for 291 - 356 ohms between the signal terminal 4 and the low reference terminal 3 with the Dim - switch pressed.

• If not between 291 - 356 ohms
Replace the S27 Head-Up Display Switch.

• If between 291 - 356 ohms

5. Test for 575 - 704 ohms between the signal terminal 4 and the low reference terminal 3 with the Up switch pressed.

• If not between 575 - 704 ohms
Replace the S27 Head-Up Display Switch.

• If between 575 - 704 ohms

6. Test for 1K - 1.2K ohms between the signal terminal 4 and the low reference terminal 3 with the Down switch pressed.

• If not between 1K - 1.2K ohms
Replace the S27 Head-Up Display Switch.

• If between 1K - 1.2K ohms

7. Test for 1.7K - 2.1K ohms between the signal terminal 4 and the low reference terminal 3 with the Page switch pressed.

• If not between 1.7K - 2.1K ohms
Replace the S27 Head-Up Display Switch.

• If between 1.7K - 2.1K ohms

8. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

Control Module References Control Module References for instrument cluster or head-up display replacement, programming, and setup

pro multis Credits:Operation CHARM About Operation CHARM