TM 10-3930-675-24-1
COOLING FAN OPERATION AND FAN CONTROL TROUBLESHOOTING
THIS WORK PACKAGE COVERS
Error Code 166 - Cooling Fan Speed, Wiring Circuit
Error Code 426 - Fording Level Switch, Circuit Input
Failure
Error
Error Code 167 - Cooling Fan Speed, Short Circuit Fail-
ure
INITIAL SETUP
References
TM 10-3930-675-10
Current Supply (A34738.0200) (WP 0048 00-31)
ECS Electrical Servo (A34648.0200) (WP 0048 00-5)
NOTE
Refer to WP 0004 00 for additional troubleshooting guidance, information, and illustrations that
locate critical components.
Refer also to illustration at end of work package for component location.
Table 1. Error Code 166 - Cooling Fan Speed, Wiring Circuit Failure Troubleshooting Procedures.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 166 - Cooling Fan Speed, Wiring 1. Enter "DIAG SERVO" 11(13) a. If no "OUTPUT" mA values
Circuit Failure.
in the diagnostic menu and
display, enter into diagnostic
observe the FAN "OUTPUT"
menus to check vehicle
and "INPUT" should have mA
temperature sensors for proper
values.
operation.
b. If no "INPUT" mA values
display, continue with step 2.
2. Enter
"DIAG
EXTRA a. If no voltage (10 to 22V) is
TEST OR INSPECTION-
FUNCT." (11(13). Check
found, disconnect X158 and
DIAG SERVO
11(13)
voltage at X158 between pin
check the resistance on the
OUTPUT/INPUT
FAN
0mA
0mA
10 and ground while changing
loose part of X158 between 9
BL.VALVE 0.00V
0mA
the fan speed using the +/-
and pin 10. Resistance should
menu selection buttons (WP
be 8 to 10 Ohms.
should vary with fan speed; 10
disconnect
ECU
(790)
to 22V.
connector 2 and check pin 13
for damage and check
continuity of wire A15810
(WP 0048 00-8).
c. Repair or replace damaged
wires or connectors (WP 0113
00 00).
