CNH FPT Advanced Engine Diagnostics Index:

Table of Contents
Starting and Charging ………………………………………………………………………………………………………………….. 4
Testing 12V Alternator Current and Voltage at Idle ……………………………………………………………………… 4
Testing 24V Alternator Current and Voltage at Idle ……………………………………………………………………… 7
Alternator AC Ripple/Diode Test ……………………………………………………………………………………………… 11
Parasitic Drain Testing (current clamp method) …………………………………………………………………………. 14
Switch and Sensor Testing: ………………………………………………………………………………………………………… 22
Throttle Switch ………………………………………………………………………………………………………………………. 22
Inductive Floating Ground Sensor…………………………………………………………………………………………….. 24
Accelerator Pedal Position Sensor ……………………………………………………………………………………………. 32
Hall Effect Position Sensor – …………………………………………………………………………………………………….. 34
Camshaft Sensor – Inductive ……………………………………………………………………………………………………. 36
AC Excited Inductive Sensor …………………………………………………………………………………………………….. 38
Dual Tracing – Camshaft Position vs Crankshaft Position Sensor …………………………………………………… 40
Coolant Temperature Sensor …………………………………………………………………………………………………… 42
Exhaust Sensors ………………………………………………………………………………………………………………………… 44
Titania Lambda Sensor ……………………………………………………………………………………………………………. 44
Zirconia Lambda Sensor ………………………………………………………………………………………………………….. 47
Lambda (Oxygen) Sensor Heater ……………………………………………………………………………………………… 49
Bosch LSU 4.2 Broadband ……………………………………………………………………………………………………….. 52
Pressure Sensors ………………………………………………………………………………………………………………………. 60
Intake Air Pressure Sensor ………………………………………………………………………………………………………. 60
Fuel Pressure Sensor ………………………………………………………………………………………………………………. 62
Analog MAP Sensor ………………………………………………………………………………………………………………… 64
Digital MAP Sensor …………………………………………………………………………………………………………………. 66
TMAP sensors (turbocharged common rail diesel) ……………………………………………………………………… 68
Fuel System Diagnostic Testing …………………………………………………………………………………………………… 71
Diesel Relative Compression Test …………………………………………………………………………………………….. 71
MPROP Fuel Quantity Control Valve …………………………………………………………………………………………. 74
Common Rail Injector at Idle (using a low-current clamp) …………………………………………………………… 76
Common Rail Injector Under Acceleration ………………………………………………………………………………… 79
Common-Rail Return Leakage Testing ………………………………………………………………………………………. 82
Unit Injector (using a low-current clamp and two BNC leads) ……………………………………………………… 88
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Component Diagnostic Testing …………………………………………………………………………………………………… 91
Diesel Glow Plugs …………………………………………………………………………………………………………………… 91
Single Glow Plug (using low-current clamp) ………………………………………………………………………………. 94
Exhaust Gas Recirculation – (EGR) solenoid valve ……………………………………………………………………….. 97
Idle Speed Control Valve – Rotary Solenoid ……………………………………………………………………………… 100
Idle Speed Control Valve – Electromagnetic …………………………………………………………………………….. 102
4-Wire Stepper Motors …………………………………………………………………………………………………………. 104
Throttle Servomotors ……………………………………………………………………………………………………………. 107
Variable-Speed Engine Cooling Fan ………………………………………………………………………………………… 110
Pressure Pulse Testing ……………………………………………………………………………………………………………… 113
Triggered Cranking Exhaust Test …………………………………………………………………………………………….. 113
Triggered Engine Idle Test ……………………………………………………………………………………………………… 115
Vacuum – Triggered Engine Cranking Test ……………………………………………………………………………….. 117
Communications System Testing ………………………………………………………………………………………………. 119
CAN Bus Testing / Diagnostics ……………………………………………………………………………………………….. 119
K-line of ISO9141-2 & keyword 2000485A ………………………………………………………………………………. 122