Cooling System Diagnosis Chart - Jeep Wrangler 2001 Service Manual

TJ
COOLING (Continued)
CONDITION
TEMPERATURE GAUGE READS
LOW
TEMPERATURE GAUGE READS
HIGH OR THE COOLANT
WARNING LAMP ILLUMINATES.
COOLANT MAY OR MAY NOT BE
LOST OR LEAKING FROM THE
COOLING SYSTEM
2001 JEEP WRANGLER

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
operating OK?
4. Coolant level low in cold ambient
temperatures accompanied with
poor heater performance.
5. Improper operation of internal
heater doors or heater controls.
1. Trailer is being towed, a steep
hill is being climbed, vehicle is
operated in slow moving traffic, or
engine is being idled with very high
ambient (outside) temperatures and
the air conditioning is on. Higher
altitudes could aggravate these
conditions.
2. Is the temperature gauge reading
correctly?
COOLING
CORRECTION
1. (Refer to 25 - EMISSIONS
CONTROL - DESCRIPTION) for
On-Board Diagnostics and DTC
information. Replace thermostat if
necessary.
2. Check the temperature sensor
connector. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - SCHEMATIC -
ELECTRICAL) Repair connector if
necessary.
3. Check gauge operation. (Refer to
8 - ELECTRICAL/INSTRUMENT
CLUSTER/ENGINE
TEMPERATURE GAUGE -
DESCRIPTION) . Repair as
necessary.
4. Check coolant level in the coolant
reserve/overflow tank and the
radiator. Inspect system for leaks.
Repair leaks as necessary. Refer to
the Coolant section of the manual
text for WARNINGS and
CAUTIONS associated with
removing the radiator cap.
5. Inspect heater and repair as
necessary. (Refer to 24 - HEATING
& AIR CONDITIONING -
DIAGNOSIS AND TESTING) for
procedures.
1. This may be a temporary
condition and repair is not
necessary. Turn off the air
conditioning and attempt to drive the
vehicle without any of the previous
conditions. Observe the temperature
gauge. The gauge should return to
the normal range. If the gauge does
not return to the normal range,
determine the cause for overheating
and repair. Refer to Possible
Causes (2-20).
2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - SCHEMATIC -
ELECTRICAL). Repair as
necessary.
7s - 3