21.1 SPN 70/FMI 13 This fault is typically the J1939 Park Brake Switch signal from Source #1 is missing. 21.1.1 Missing Signal from Source #1,…

This diagnostic condition is typically the EGR valve stuck open. 19.3.1 Valve Function Check Check as follows: 1. Turn the ignition ON (key ON, engine…

This diagnostic condition is typically a circuit failed high. 19.2.1 EGR Valve Position Circuit Check Check as follows: 1. Check for multiple codes. [a] If…

This diagnostic condition is typically the EGR valve position circuit failed high. 19.1.1 EGR Valve Position Circuit Check Check as follows: 1. Disconnect the EGR…

To determine if abnormal radiator coolant flow is causing high engine coolant temperature, perform the following: 1.Install a sight glass with string (both ends) to…

To determine if combustion gases in coolant is causing high engine coolant temperature, perform the cylinder compression test. Refer to section 13.9.1. 13.9.1 Cylinder Compression…

To determine if a faulty water pump is causing high engine coolant temperature, perform the following: 1. Remove the water pump, (gear case mounted) or…

To determine if faulty thermostats are causing high engine coolant temperature, perform the following: 1. Remove thermostat from the thermostat housing; refer to appropriate service…

To determine if an inoperative thermo-modulated fan is causing high engine coolant temperature, test the thermo-modulated fan; refer to OEM guidelines. 1. If the thermo-modulated…

To determine if misadjusted fan belts are causing high engine coolant temperature, perform the following: 1. Test fan belt(s) tension; refer to appropriate service manual,…