MTU 12 V 4000 L62FB Operating Instructions Manual page 120

646 – Al Knock Intensity
Red alarm
Associated parameter 2.1200.934
Cause
Knock intensity exceeded
(extreme knocking detected)
649 – Al Req Angle Throttle A
Red alarm
Associated parameter 2.1200.935
Cause
Opening angle of throttles A
exceeded
650 – Al Req Angle Throttle B
Red alarm
Associated parameter 2.1200.936
Cause
Opening angle of throttles B
exceeded
651 – AL Preheating Error
Yellow alarm.
Associated parameter 1.1480.101
Cause
Engine preheating faulty
652 – AL GET Comm Lost
Red alarm
Associated parameter 1.4510.996
Cause
CAN bus communication for
knock control faulty
120 | Troubleshooting | MS150098/02E 2016-11
Corrective action
1. Check gas quality if feasible (methane number).
2. Check emissions.
3. Check combustion chamber.
Corrective action
1. Check charge-air pressure reserve.
2. Intake air temperature outside TVU data.
3. Check compressor for contamination.
4. Reduce power.
Corrective action
1. Check charge-air pressure reserve.
2. Intake air temperature outside TVU data.
3. Check compressor for contamination.
4. Reduce power.
Corrective action
1. Low coolant.
2. Missing differential pressure in coolant system.
3. Coolant pump does not start, is faulty.
Corrective action
1. Check cabling.
2. Check power supply.
3. Carry out restart of ECU, EMU & knock control.
4. Check settings with device-specific dialog software (XD10).