OM3005.3 7/96 Operation - Section 3 Instrument Panel and Controls Page 3-23 (52) EQUAL FAULT Light Cummins "Quantum" Engine Electronic Control System The charge condition of the two 12 Volt batteries is monitored to make sure that both batteries are being charged equally. The Equal Fault Light will illuminate if more than a 0.85 volt variance between the two batter- ies is detected. The following information (items 55 through 59, Figure 3-6) relates to the Cummins "Quantum" Engine Elec- tronic Control System. (53) CHECK TRANS Light If an abnormal engine condition develops, the control system will record a "fault" code associated with that condition.
By use of a series of indicator lamps and switches, the system will display the numerical "fault" code. The ATEC system has a built in computer that monitors various functions and performances. When the com- puter senses that the system is not performing prop- erly, the CHECK TRANS light comes "On" to warn and alert the operator that a problem has occurred and that the vehicle should be serviced as soon as possible. The CHECK TRANS light will come "On" when the ignition is turned "On". After about two seconds, the light will go "Off". This provides a light bulb check and a system check.
When the keyswitch is turned "On", the lamps (56, 57, 58) should illuminate for about 2 seconds and then turn "Off", if no "faults" are detected in the system. This is a system lamp test. In cold weather, when the transmission oil is below -10 o F (-23 o C), the DO NOT SHIFT lights on the range selector and the CHECK TRANS light will stay on after the engine is started. The transmission will stay in NEUTRAL, regardless of which range is selected until the oil is warmer than -10 o F (-23 o C). When the trans- mission oil warms up, the CHECK TRANS and DO NOT SHIFT lights will turn off and the transmission will operate in first gear or reverse only.
At 20 o F (-7 o C), the transmission may be operated safely in all ranges. If a light stays ON, or FLASHES, then active "faults" have been detected by the system and the engine should not be started until the condition has been corrected. Refer to DETERMINING "FAULT" CODES. During engine operation, if a "fault" is detected in the system, a light associated with that condition will turn "ON" and stay on for "Warning faults", or it will turn "ON and FLASH" for more severe faults that can affect engine operation and require immediate attention. "Warning" faults (light ON) are ones that require attention in the near future, but in most conditions will not greatly affect performance.
If the transmission oil temperature reaches 250 o F (121 o C), the CHECK TRANS indicator light will come "On". The ECU (Electronic Control Unit) will inhibit operation of the truck in higher gears. NOTE: The Transmission Temperature Gauge (23) indicates the converter temperature. The ECU senses oil temperature in the sump. The two temperatures may be different. "Severe" faults (light FLASHING) are ones that require immediate attention, because the engine could be significanly affected. (54) ALT. FAULT Light This light will illuminate if the alternator output exceeds 30 VDC, or battery voltage is less than 24 VDC, or if voltage for each battery differs more than 0.75 V.
Active fault conditions MUST be corrected as soon as possible. Sump Oil Temperature Do Not Shift Light Check Trans Light Truck Operation -10°F (-24°C) And BELOW ON ON NEUTRAL ONLY -9°F (-23°C) to + 19°F (-7°C) OFF OFF NEUTRAL, 1st (FIRST), & REVERSE Only + 20°F (-6°C) And ABOVE OFF OFF Full Operation In All Ranges