Jeep KJ 2005 Service Manual page 211

7 - 6 COOLING
COOLING (Continued)
COOLING SYSTEM DIAGNOSIS CHART - GAS
ENGINE
CONDITION
TEMPERATURE GAUGE READS
LOW
COOLING SYSTEM DIAGNOSIS CHART
POSSIBLE CAUSES
1. Has a Diagnostic Trouble Code
(DTC) been set indicating a stuck
open thermostat?
2. Is the temperature sending unit
connected?
3. Is the temperature gauge oper-
ating OK?
4. Coolant level low in cold ambi-
ent temperatures accompanied
with poor heater performance.
5. Improper operation of internal
heater doors or heater controls.
6. Electric fan functioning when not
required.
CORRECTION
1. Refer to (Refer to 25 - EMIS-
SIONS CONTROL - DESCRIP-
TION) for On-Board Diagnostics
and DTC information. Replace ther-
mostat if necessary.
2. Check the temperature sensor
connector. (Refer to 7 - COOLING/
ENGINE/ENGINE COOLANT TEMP
SENSOR - DESCRIPTION). Repair
connector if necessary.
3. Check gauge operation. Repair
as necessary.
4. Check coolant level in the cool-
ant pressure botttle and the radia-
tor. Inspect system for leaks.
Repair leaks as necessary.
5. Inspect heater and repair as
necessary. (Refer to 24 - HEATING
& AIR CONDITIONING - DIAGNO-
SIS AND TESTING)
6. Inspect electric fan for proper
operation. Refer to Electric Cooling
Fan in this section. Refer to group
8W for electric cooling fan and
relay circuit schematic data.
KJ