OM3020.3 02/01 Operation - Section 3 Instrument Panel & Indicator Lights Page 3-37 A4. NOT USED Reserved for future use or options. This amber indicator will illuminate when the manually operated Manual Backup switch (3, Figure 3-6, Instrument Panel) is turned “on”. B4. Manual Backup Lights C4. Engine Shutdown Timer - 5 Minute Idle When the Engine Shutdown Timer switch has been activated (2, Figure 3-6, Instrument Panel), this indicator light will illuminate to indicate that the shutdown timing sequence has started. Refer to Instrument panel for operation of this switch. D4.
Retard Speed Control Indicator This amber light is illuminated when the RSC switch mounted on the console is pulled out to the “On” position. The light indicates the retarder is active. It is for feedback only and does not signal a problem. E4. Check Engine This amber “Check Engine” indicator will illuminate if a malfunction is detected by the engine electronic control system. If this indicator illuminates, truck operation may continue, but maintenance personnel should be alerted as soon as possible .