TSB:
Quote:
NUMBER: 08-043-05
GROUP: Electrical
DATE: August 11, 2005
THIS BULLETIN IS BEING PROVIDED IN ADVANCE. DO NOT PERFORM ANY
ACTIONS RELATED TO THIS BULLETIN UNTIL AUGUST 26, 2005. THE DRB III
SOFTWARE VERSION MUST BE AT LEVEL 62.2 TO PERFORM THIS BULLETIN. THE
DRB III SOFTWARE WILL BE AVAILABLE ON TechCONNECT BY AUGUST 26, 2005.
FOR MARKETS OUTSIDE OF THE UNITED STATES AND CANADA, THE DRB III
VERSION 62.2 SOFTWARE WILL BE AVAILABLE ON CINONConnect AND
TechCONNECT BY AUGUST 26, 2005. THE DRB III VERSION 62.2 SOFTWARE WILL
ALSO BE AVAILABLE ON THE ITIS DVD SEPTEMBER 2005 RELEASE.
SUBJECT:
Engine Temperature Gauge - Indicator Reads A Higher Temperature Than Actual
OVERVIEW:
This bulletin involves reprogramming the instrument cluster control (CCN)
module.
MODELS:
2005 (KJ) Liberty / Cherokee
NOTE: This bulletin applies to vehicles equipped with a 2.8L turbo diesel
engine
(sales code ENR).
SYMPTOM/CONDITION:
The customer may notice that the engine temperature gauge may indicate that
the engine
temperature is high. In hot ambient temperatures, and under certain driving
conditions of
extended uphill driving while towing a trailer, the engine temperature
indicator may indicate
slightly above the 3/4 normal operating temperature mark on the temperature
gauge (but
below the engine hot temperature markings). This condition may be caused by
an incorrect
calibration of the of the engine temperature gauge.
New CCN module software corrects the old engine temperature gauge
calibration.
DIAGNOSIS:
If the engine and the cooling system are operating correctly, and the above
condition is
present, then perform the Repair Procedure.
SPECIAL TOOLS/EQUIPMENT REQUIRED:
CH6000A Scan Tool (DRBIII®)
NUMBER: 08-043-05
GROUP: Electrical
DATE: August 11, 2005
CH7000A/7001A J1962 Cable with red DRBIII® connector
REPAIR PROCEDURE:
NOTE: Before proceeding verify that the DRBIII® software version is at level
62.2.
1. Connect the DRBIII® to the vehicle Data Link Connector (DLC)
2. Turn the ignition switch to the "ON" position.
3. Using the DRBIII® scan tool recalibrate the instrument temperature gauge.
a. Select "DRBIII® Standalone"
b. Select "1998 - 2006 Diagnostics"
c. Select "All (Except Below)"
d. Select "Body Interior"
e. Select "Electro/Mech Cluster (MIC)"
f. Select "Miscellaneous"
g. Select "Recalibrate Temp Gauge" option.
4. If the recalibration of the instrument cluster was successful, the
DRBIII® will display
the following message: "Recalibration Successful".
5. If the version level of the original instrument cluster software allows
recalibration, but
the recalibration of the instrument cluster was NOT successful, then the
DRBIII® will
display one of the following messages: "Recalibration Failed" or "Write To
Memory
Address Failed". If one of these messages occurs repeat the above steps.
6. If the instrument cluster has already been recalibrated to the correct
software version
level, then the DRBIII® will display the following message: "Gauge Already
Recalibrated - Press Any Key to Exit".
7. The DRBIII® will display the following message if the original instrument
cluster
software version level is not the correct version level for recalibration:
"MIC Software
Version Incorrect - Press Any Key to Exit".
8. Verify that the instrument cluster engine temperature gauge has been
recalibrated by
selecting the "Recalibrate Temp Gauge" option again. The DRBIII® should
display the
following message: "Gauge Already Recalibrated - Press Any Key to Exit".
9. Turn the vehicle ignition switch to the "OFF" position
10. Disconnect the DRBIII® from the vehicle DLC.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation
No:
Description Amount
08-45-10-94 Reprogram Instrument Cluster Control (CCN)
Module - 2.8L Turbo Diesel Engine Only
0.2 Hrs.
FAILURE CODE:
AM Authorized Modification
Warp2diesel from fsm
Quote:
² Engine Temperature Message - Each time the cluster receives a message from the PCM indicating the
engine coolant temperature is within the normal operating range [up to about 124° C (255° F) for gasoline
engines, or about 110° C (230° F) for diesel engines], the gauge needle is moved to the actual relative temperature
position on the gauge scale.
² Engine Temperature High Message - Each time the cluster receives a message from the PCM indicating the
engine coolant temperature is high [above about 127° C (260° F) for gasoline engines, or 112° C (233° F) for
diesel engines], the gauge needle is moved into the center of the red warning zone on the gauge scale.
² Engine Temperature Critical Message - Each time the cluster receives a message from the PCM indicating
the engine coolant temperature is critical [above about 132° C (269° F) for gasoline engines, or 115° C (239°
F) for diesel engines], the gauge needle is moved to the high end of the red warning zone on the gauge scale.
For the gasser, the spread between normal and hot is 5 degrees F and 14f for critical. Our diesels it is 3 degrees between normal and hot and 9 degrees normal and critical. The span is tighter.
To test the following:
1) Temp sending unit measure the cylinder head next to the sending unit with engine warmed up and gauge reading normal and record. If the thermometer reads normal with the gauge at hot or critical, the sending unit, Body control Module or gauge is the problem.
2) Engine warmed up, measure the radiator top inlet and lower outlet and record the difference. If the two readings are very close when the gauge reads hot, the radiator is the problem.
3) Engine warmed up, measure the head temp near temp sensor and the engine outlet pipe where the upper radiator hose is attached and record. If the difference between cylinder head reading and the engine outlet pipe reading climbs when the gauge reads hot, the thermostat is not fully opening or there is a restriction in the cooling system.
and some electric fan info via bill.barg quoting fsm
Quote:
From the service manual.
E fan turns on when the PCM feel s like it. Many inputs including battery temperature !?!!?
The electric radiator cooling fan is controlled by the Powertrain Control Module
(PCM) through the radiator cooling fan relays. The PCM regulates fan operation
based on input from the engine coolant temperature sensor, battery temperature
sensor, air conditioning select switch and vehicle speed.
The fan is not energized during engine cranking regardless of the electrical input
from the temperature sensors and air conditioning switch. However, if engine
operation conditions warrant fan engagement, the fan will run once engine starts.
On vehicles NOT equipped with AC: The relay is energized when the coolant
temperature is above 80° C (176° F), or battery temperature sensor above -12° C
(10° F). It will then de-energize when coolant temperature drops below 82° C
(180° F), or battery temperature sensor below -9° C (16° F).
Vehicles Equipped with AC: In addition to using coolant temperature and
battery temperature sensor to control cooling fan operation, the cooling fan will
also be engaged when the air conditioning system is activated. The relay is also
energized when air conditioning is selected and coolant temperature is above 95°
C (203° F), or, air conditioning is selected and battery temperature sensor is
above 41° C (106° F). It will then de-energize when air conditioning is selected
and coolant temperature is below 92° C (198° F), or air conditioning is selected
and battery temperature is below 38° C (100° F).
MITCHELL 1 ARTICLE - 2006 ENGINE Cooling - Liberty Page 1 of 1
http://
hope this helps.