TROUBLESHOOTING INTRODUCTION - CONTINUED
VISUAL INSPECTION OF COOLING SYSTEM
Look for leaks in cooling system.
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Small amounts of coolant leakage across surface of water pump seals is normal. This leakage is required to
provide lubrication for water pump seals. Hole is provided in water pump housing to allow this coolant/seal
lubricant to drain from pump housing. Intermittent leakage of small amounts of coolant from this hole is
not an indication of defective water pump seals.
Inspect radiator for bent fins and other restrictions to air flow through radiator.
Inspect fan blades for damage.
Inspect radiator filler cap for damage. Seal surface must be clean.
Look for dirt blocking radiator fins or coating engine.
Look for loose or missing shrouds that would reduce air flow for cooling.
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Flash programming of a new rating interlock replaces old rating interlock.
This code does not need to be programmed when replacement ECM is from same engine rating.
If ECM is from a different engine rating, then these components may need to be changed: pistons, fuel injectors, other
components. Engine information ratings plate must also be changed to reflect new rating.
Some vehicle systems, such as cooling system or transmission, may also require changes when engine is rerated. Please
contact local OEM dealer for further information.
Active Diagnostic Code. An active diagnostic code describes a condition currently present in order to alert operator or
service technician to an electronic system malfunction. Refer to "Diagnostic Code" in this glossary.
Alternating Current (ac). Alternating current is an electric current that reverses direction at a regular, recurring inter-
American Wire Gage (AWG). AWG is a measure of electrical wire diameter. AWG is also a measure of electrical wire
current carrying capacity. When AWG number is smaller, diameter of wire is larger. When AWG number is larger, diam-
eter of wire is smaller.
Before Top Center (BTC). BTC is 180 degrees of crankshaft rotation before piston reaches top center position in nor-
mal direction of rotation.
Breakout Harness. Breakout harness is a test harness designed to connect into vehicle harness or engine harness. This
connection allows a normal circuit operation and simultaneously provides a breakout T in order to measure signals.
Boost Pressure Sensor. Difference between turbocharger outlet pressure and atmospheric pressure is commonly
referred to as "boost".
Bypass Circuit. A bypass circuit is a circuit used as a substitute circuit for an existing circuit. A bypass circuit is typi-
cally used as a test circuit.
CAT Data Link. CAT Data Link is a serial communication port used for communication with other microprocessor-
Code. Refer to "Diagnostic Code" or "Event Code" in this glossary.