Table 157. The following conditions will turn the Fan ON for Illustration 67

210

TM 9-2320-312-24-2

Troubleshooting Section

Table 157

The following conditions will turn the Fan ON for Illustration 67.

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 circuit for the switch is closed or the switch is on.

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 the ON position 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 cooling fan air solenoid valve

The solenoid is energized.

OEM installed cooling fan relay

There is an open circuit on the coil side of the relay.

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.

g00845731

Illustration 68

This schematic represents the on/off fan with a normally open relay connection and an A/C high pressure switch connected to the ECM input.