412 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
Operational Voltage Checks for EFP Sensor without Breakout Harness (Check with bre
akout box
connected [X1 and X2 only] to the ECM and engine harness.)
Test Point
EST voltage readin gs:
Signal to ground
Spec Checks
X2–3 to
X1–6
0.66 V
5 kPa (0.75 psi) Voltage with key-on engine-off.
X2–3 to
X1–6
1.65 V
138 k Pa (20 psi) Voltage with key-on engine-off.
X2–3 to
X1–6
3.13 V
345 k Pa (50 psi) Voltage with key-on engine-off.
X2–3 to
X1–6
4.1 V
483 k Pa (70 psi) Rated speed, full load
EFP Diagnostic Trouble Codes
DTC 136 = Signal voltage was < 0.039 V for more than 0.35 second
DTC 137 = Signal voltage was > 4.9 V for more than 0.3
5 second
DTC 371 = Engine fuel pressure is above normal operating range
DTC 372 = Engine fuel pressure is below normal operating range
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.