6 PERFORMANCE DIAGNOSTICS 243
5. Ru n engine at low idle and compare KOEO BCP
signal voltage to low idle signal voltage.
• If BCP low idle signal vo lta ge is more than
KOEO BCP signal voltage, when engine
brake is inactive, diagnose BCP sensor,
circuit, and engine brake components. The
BCP voltage reading should be zero psi;
however, BCP values may fluctuate as
much as 345 kPa (50 psi). Electromagnetic
interference (EMI) or ground shift can cause
an insignificant voltage shift that does not
indicate a problem .
• If BCP low idle signal voltage is equal to
KOEO B C P signal voltage , co nt inu e with
step 6.
6. Run engine at high idle and compare KOEO BCP
signal voltage to high idle signal voltage.
• If BCP high idle signal voltage is more than
KOEO BCP signal voltage, when engine
brake is inactive, diagnose BCP sensor,
circuit, and engine brake components. The
BCPvoltagereadingshouldbezeropsi;
however, BCP values may fluctuate as
much as 345 kPa (50 psi). Electromagnetic
interference (EMI) or ground shift can cause
an insignificant voltage shift that does not
indicate a problem .
• If BCP high idle signal voltage is equal
to KOEO BCP signal voltage, there is no
problem with the BCP s ensor signal or the
engine brake.
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.
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