Circuit Description
The head-up display (HUD) monitors the HUD information-down switch signal circuit in order to perform the switch functions. When the HUD information-down switch is depressed and the ignition is in the RUN position, the switch signal to the HUD is low. When the HUD detects that the HUD information-down switch signal is low for greater than 60 seconds, DTC B3621 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3620 Head Up Display (HUD) Information Down Switch Circuit
Conditions for Running the DTC
The ignition is RUN.
Conditions for Setting the DTC
The HUD detects that the HUD information down switch signal circuit is low for greater than 60 seconds.
Action Taken When the DTC Sets
The HUD ignores the malfunctioning switch circuit.
Conditions for Clearing the DTC
| • | The current DTC clears when fault is no longer present but all history codes remain. |
| • | The HUD receives a clear code command from the scan tool. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Head Up Display Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the HUD image down switch operate correctly? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the HUD Adjust Display Down Switch parameter display only ACTIVE on the scan tool when the HUD image down switch is pressed and released? | Go to Step 4 | Go to Step 6 |
4 | Test the HUD image down switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
5 | Inspect for poor connections at the HUD switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the HUD module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the HUD switch. Refer to Switch Replacement - Ignition and Start, DIC Display and HUD Dimmer . Did you complete the replacement? | Go to Step 9 | -- |
8 | Replace the HUD. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | System OK | Go to Step 2 |
