Eop Circuit Operation - Navistar International DT 466 Diagnostic/Troubleshooting Manual

7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

EOP Circuit Operation

Figure 445 EOP circuit diagram
The EOP sensor is supplied with a 5 V reference
voltage at Pin 2 from ECM Pin X1–14. The EOP
sensor is grounded at Pin 1 from ECM Pin X1–6. The
EOP sensor returns a variable voltage signal from Pin
3 to ECM Pin X2–7.
Fault Detection / Management
When the EOP signal voltage is detected out of range
high or low, the ECM will cause the engine to ignore
the EOP signal and disable the EWPS.
EOP Diagnostic Trouble Codes (DTCs)
DTCs are read using the EST or by counting the
flashes from the amber and red ENGINE lamp.
DTC 211
EOP signal out-of-range low
• DTC 211 is set by the ECM when the EOP signal
is less than 0.039 V for more than 0.35 second.
• DTC 211 can be set due to an open or short to
ground on the signal circuit, a failed ICP sensor
or an open V circuit or V
REF
• When DTC 211 is active the amber ENGINE lamp
is illuminated.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
short to ground.
REF
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
DTC 212
EOP signal out-of-range high
• DTC 212 is set by the ECM when the EOP signal
is greater than 4.9 V for more than 0.35 second.
• DTC 212 can be set due to signal circuit short to
V or B+, or a failed EOP sensor.
REF
• When DTC 212 is active the amber ENGINE lamp
is illuminated.
DTC 225
EOP sensor signal in-range fault
• DTC 225 is set by the ECM when the EOP
signal voltage is greater than 207 kPa (30 psi)
for 8 seconds or more with the ignition key-on
engine-off.
• DTC 225 can be set due to an open signal ground,
V shorted to voltage source above 5.5 V, biased
REF
circuit, failed EOP sensor.
• When DTC 225 is active the amber ENGINE lamp
is illuminated.
427