Table 154. The following conditions will turn the Fan ON for Illustration 64

207

TM 9-2320-312-24-2

Troubleshooting Section

Table 154

The following conditions will turn the Fan ON for Illustration 64.

Circuit

Condition that will turn the Fan ON

Coolant temperature sensor

The coolant temperature is greater than 96 C (205 F).

A diagnostic code for the coolant temperature sensor is

active.

Exhaust brake

The "Fan with Exhaust Brake ON" parameter is programmed

to "YES".

The exhaust brake is on at least two seconds.

OEM installed A/C high pressure switch

The "A/C Switch Fan On-Time" is programmed to a value

above 0.

The switch circuit is open or on.

The external timer is counting or the ECM timer is counting.

The engine rpm is less than 2750 rpm.

The engine is cranking. The engine has been running two

seconds or the ignition key is ON and the engine OFF.

Air inlet temperature sensor

The temperature in the air inlet manifold is greater than 87 C

(189 F).

The temperature in the air inlet manifold is greater than 72 C

(162 F) while the boost pressure is greater than 70 kPa

(10 psi).

OEM installed manual fan override switch

There is an open circuit in the switch or the switch is ON.

OEM installed cooling fan air solenoid valve

Open solenoid circuit

Circuit breaker for the cooling fan

Tripped breaker or open circuit

Dedicated PTO on/off switch

The "PTO Configuration" is programmed.

The "PTO Activates Cooling Fan" is programmed.

There is a short circuit in the switch or the switch is on.

g00766679

Illustration 65

This schematic represents an on/off fan with a direct solenoid connection to the ECM and the A/C high pressure switch is not connected to

the ECM input.