Navistar International DT 466 Diagnostic/Troubleshooting Manual page 446

442 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
EWPS Diagnostic Trouble Codes (DTCs)
DTCs are read using the EST or by counting the
flashes from the amber and red ENGINE lamp.
DTC 323
ECT below warning/critical level
• DTC 323 is set by the ECM when coolant is low.
When the EWPS mode is 3-way protection and
DTC 323 is active, the engine will shutdown. The
ECM will log the engine hours and odometer
reading at the time of occurrence.
shutdown, the engine can be restarted for thirty
seconds. When the coolant has returned to
correct levels, DTC 323 will become inactive.
NOTE: If coolant level is correct, see "ECL Sensor"
(page 370). An ECL signal shorted to ground can
cause DTC 323.
DTC 321
ECT above warning level
• DTC 321 is set by the ECM when the engine
coolant temperature is above 110 °C (230 °F).
The ECM illuminates the red ENGINE lamp and
sounds the audible alarm. When the temperature
drops below 110 °C (230 °F) the DTC will become
inactive. For diagnostics, see "Engine Symptoms
Diagnostics" – Section 4 (page 101).
• For high altitude applications (103 kPa [15 psi]
radiator cap), DTC 321 is set by the ECM when
the engine coolant temperature is above 113 °C
(235 °F). When the temperature drops below 113
°C (235 °F) the DTC will become inactive.
DTC 322
ECT above critical level
• DTC 322 is set by the ECM when the engine
coolant temperature is above 112 °C (234 °F).
The ECM illuminates the red ENGINE lamp and
sounds the audible alarm. When the temperature
drops below 112 °C (234 °F) the DTC will become
inactive. For diagnostics, see "Engine Symptoms
Diagnostics" – Section 4 (page 101).
• For high altitude applications (103 kPa [15 psi]
radiator cap), DTC 321 is set by the ECM when
the engine coolant temperature is above 116 °C
(241 °F). When the temperature drops below 116
°C (241 °F) the DTC will become inactive.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
DTC 325
Power reduced, matched to cooling system
performance
• DTC 325 is set by the ECM when the cooling
system temperature exceeds 107 °C (225 °F).
At this temperature the ECM will reduce the fuel
delivered to the engine. When the temperature
drops below 107 °C (225 °F) the DTC will become
inactive and the engine will return to normal
operation.
After the For each Celsius degree of temperature the fuel
will be reduced by 6 percent. For each Fahrenheit
degree of temperature the fuel will be reduced
by 3 percent. This reduces the heat produced
by the engine and reduces the burden on the
cooling system. The vehicle speed will also be
reduced and allow the operator to downshift and
increase the efficiency of the cooling system. As
the temperature is reduced, the compensation
level is reduced until the temperature drops below
107 °C (225 °F) and normal operation is resumed.
For high altitude applications (103 kPa [15 psi]
radiator cap), as the temperature is reduced,
the compensation level is reduced until the
temperature drops below 111 °C (232 °F) and
normal operation is resumed.
DTC 325 does not illuminate the ENGINE warning
lamp.
DTC 316
ECT unable to reach commanded set point
NOTE: DTC 316 only indicates the engine has not
been able to reach operating temperature. It does not
indicate an electronic fault.
• DTC 316 is set if the engine does not reach
operating temperature. DTC 316 will only be set
with engines that have Cold Ambient Protection
(CAP) strategy enabled. DTC 316 is set after
the engine has run for more than 120 minutes
and has not exceeded 66 °C (151 °F) for engine
coolant temperature. DTC 316 can be cleared
with the EST.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.