For 1990-2009 cars only
The instrument cluster provides information to the HUD (optional) through serial parallel interface (SPI) lines. The following list includes the information provided:
| • | Display on/off |
| • | Turn signals |
| • | High beam |
| • | Unit mode (English/metric) |
| • | CHECK GAUGES |
| • | Speedometer biasing status |
Ensure that the instrument cluster is connected when diagnosing problems associated with the HUD.
