Navistar International DT 466 Diagnostic/Troubleshooting Manual page 302

298 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
DTC 354 – VGT control under duty cycle
DTC 354 is set when the ECM overcompensates by decreasing duty cycle to the VGT to achieve the
desired boost/back pressure.
Possible Cause
BAP sensor bias high
MAP sensor bias high
EBP sensor bias high
Open Exhaust (no muffler)
ICP sensor bias low
ICP system integrity
Injector operation / part number
Exhaust restriction (muffler or catalytic
converter)
VGT control circuit short to B+.
VGT actuator or vanes stuck
DTC 355 – VGT overspeed
DTC 355 is set when the ECM detects turbo over speed several times in a specific period of time (dependent
on ECM calibration). Turbo speed is estimated by engine speed, boost pressure, and barometric pressure.
Possible Cause
High intake restriction
Intake / CAC system leak (pipes, loose
clamps, hoses)
Restricted CAC system
VGT actuator or vanes sticking
Open exhaust (no muffler)
BAP sensor bias
MAP sensor bias high
EBP sensor bias low
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Comment
Check sensor signal voltage. See "BAP Sensor" (page 314).
Check sensor signal voltage. See "MAP Sensor" (page 500).
Check sensor signal voltage. See "EBP Sensor" (page 359).
Inspect exhaust system.
Check sensor signal voltage. See "ICP Sensor" (page 457).
Do "Performance Diagnostics" (page 205).
Check previous repairs. Do "Performance Diagnostics" (page
205).
Inspect exhaust. Do"Performance Diagnostics" (page 205).
Do VGT Pin-Point Diagnostics. See "VGT Actuator" (page 524).
Do "Performance Diagnostics" (page 205).
Comment
Do "Performance Diagnostics" (page 205).
Do "Performance Diagnostics" (page 205).
Do "Performance Diagnostics" (page 205).
Do "Performance Diagnostics" (page 205).
Inspect exhaust system
Check sensor signal voltage. See "BAP Sensor" (page 314).
Check sensor signal voltage. See "MAP Sensor" (page 500).
Check sensor signal voltage. See "EBP Sensor" (page 359).
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.