LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2004 >> XLR >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel System Displays, Gauges And Console >> Diagnostic Information and Procedures >> Head Up Display (HUD) Inoperative >> Test Description

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 6:  Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the VF dimming signal circuit is shorted to ground.
Head Up Display (HUD) Inoperative

Step Action Yes No
Schematic Reference: Head Up Display Schematics 
1 Did you review the system operation and perform the necessary inspections? Go to Step 2  Go to Symptoms - Instrument Panel, Gages and Console 
2
  1. Turn the ignition ON, with the engine OFF.
  2. Turn the head up display (HUD) ON.
  3. Adjust the HUD dimmer switch to full intensity.
Is the HUD display visible?		 Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3 Test the ignition 1 voltage circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Repairs.
Did you find and correct the condition?		 Go to Step 13  Go to Step 4 
4 Test the ground circuit of the HUD for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Repairs.
Did you find and correct the condition?		 Go to Step 13  Go to Step 5 
5
  1. Turn the ignition OFF.
  2. Disconnect the HUD switch.
  3. Connect a fused jumper between the ignition 1 voltage circuit of the HUD switch and the HUD switch signal circuit. Refer to Circuit Testing in Wiring Systems.
  4. Turn the ignition ON, with the engine OFF.
Does the HUD illuminate?		 Go to Step 10  Go to Step 6 
6  Test the HUD switch signal circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Repairs.
Did you find and correct the condition?		 Go to Step 13  Go to Step 7 
7
  1. Leave fused jumper from step 5 connected.
  2. Connect another fused jumper between the ignition 1 voltage circuit of the HUD switch and the illuminated display signal circuit of the HUD. Refer to Circuit Testing in Wiring Systems.
  3. Turn the ignition ON, with the engine OFF.
Does the HUD illuminate?		 Go to Step 9  Go to Step 10 
8 Test the illuminated display signal circuit of the HUD for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Repairs.
Did you find and correct the condition?		 Go to Step 13  Go to Step 9 
9 Inspect for poor connections at the harness connector of the HUD module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 13  Go to Step 11 
10 Inspect for poor connections at the harness connector of the HUD switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 13  Go to Step 11 
11 Replace the HUD switch. Refer to Head Up Display Switch Replacement .
Did you complete the replacement?		 Go to Step 13  -
12 Replace the HUD. Refer to Head Up Display Replacement .
Did you complete the replacement?		 Go to Step 13  -
13 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 2 
scientia non olet · About LEMON Manuals