2008 dodge compass .. launch tool is only showing left rear right front and spare tire locations ...alldata info is showing similiar ...like there is only 3 tire locations available for this car .....is anyone familiar with the chrysler system ...maybe you can expain what's up with only three sensors/ ......thanks

hi there

this is from a cd manual from a 300c manual for the WCM system on the car the same as jeep i think it should be the same for your question..... we do not get to see this system very much here but the last one i did in the launch was a jeep and the operation to recode was straight forward the live data even give the id for the spare tyre

i was impressed haha 

hope this helps.......


TIRE PRESSURE MONITORING - SERVICE INFORMATION

DESCRIPTION
The Tire Pressure Monitoring (TPM) system monitors air pressure in the four road tires (excludes spare). Pressure in the spare tire is not monitored. There are two systems available on this vehicle, a base and a premium. The base
system does not specify how many tires are low or where they are located. The premium system does so. TPM alerts the driver when tire pressure falls below predetermined thresholds. The TPM systems are controlled by the Wireless Control Module (WCM), commonly referred to as the Sentry Key
Remote Entry Module (SKREEM).

There is a sensor (transmitter) in each of the vehicle’s four road wheels that operates on a 315 MHz radio frequency. Export vehicle sensors operate on a 433 MHz radio frequency. If a vehicle is equipped with the premium TPM system, transponders located in three of the four wheel wells of the vehicle are used to provide the WCM with the location of the tire pressure sensors on the vehicle. The transponders are located in the left front, right front and right rear wheel wells. An indicator lamp located in the instrument cluster and, if equipped with the premium TPM system, the Electronic Vehicle Information Center (EVIC) are used to communicate system information. For further information, refer to the Owners Manual or the appropriate diagnostic information.

OPERATION
The Tire Pressure Monitoring (TPM) system uses radio and sensor technology to monitor tire air pressure levels. Sensors, mounted to each road wheel as part of the valve stem, transmit an RF signal indicating their individual pressure to a receiver located in the Wireless Control Module (WCM), commonly referred to as the Sentry Key Remote Entry Module (SKREEM). These transmissions occur approximately once every minute at speeds over 15 mph (24 km/h). The Tire Pressure Monitoring system remains active even if no tire pressure related message is displayed.

The sensors lay dormant (Park Mode), then wake and start transmitting (Drive Mode) when the vehicle first reaches speeds over 15 mph (24 km/h). Once the wheels stop rotating for a period of approximately 20 minutes, the sensors shut down until again awaken. Although not transmitting as when in Drive Mode, while in Park Mode, the sensors still transmit approximately once every 13 hours to let the receiver know air pressure status at that time. Sensors will also transmit when a pressure change of one psi (seven kPa) or more is detected during that period.

If the vehicle is equipped with the premium TPM system, transponders located in three of the four wheel wells of the vehicle are used to provide the WCM with the location of the tire pressure sensors on the vehicle. The transponders are located in the left front, right front and right rear wheel wells. A fourth transponder is not necessary in the remaining wheel well due to the process-of-elimination theory. Once the system knows the location of the first three sensors it assumes the location of the fourth tire pressure sensor is in the left rear tire.

If the system detects that the tire pressure in any road tire is going low, beyond the Low Pressure (lamp) ON threshold, the TPM system will continuously illuminate an indicator lamp. If equipped with the premium TPM system, a message will be displayed in the instrument cluster. The text message will indicate which tire is low and the display will show all current tire pressures, the low tire will be flashing with its pressure value. This message will be displayed for the rest of the ignition cycle, or until the Low Tire pressure condition has been corrected. A chime will sound upon initial detection. Once pressure in the suspect tire raises above the Low Pressure (lamp) OFF Threshold, the lamp will go out and the system returns to normal within approximately two minutes time. If a message center button is pressed, the message is replaced by the new message requested; however, if the Low Tire condition has not been corrected, the Low Tire pressure message will again be displayed.

If a system fault is detected, the indicator lamp will flash on/off for 60 seconds, once every 10 minutes.

thanks for the help john ..here's the info alldata sent me from their library after i called and asked.similiar to what you posted from the chrysler manual

i think the launch info may be wrong .here's what shows on the screen 

tire 1 location pasenger front
tire 2 location driver rear 
tire 3 location spare 


here's the alldata info 

DESCRIPTION
The Tire Pressure Monitoring (TPM) system monitors air pressure in the four road tires (excludes spare).
Pressure in the spare tire is not monitored.
There are two tire pressure monitoring systems available, a base system and a premium system. The base
system does not specify how many tires are low or where they are located. The premium system does so.
The Base TPM system consists of tire pressure monitoring sensors attached to each road wheel through the
valve stem mounting hole, a central receiver module (WCM) and an indicator lamp.
The Premium TPM system consists of tire pressure monitoring sensors attached to each road wheel through the
valve stem mounting hole, a wireless control module (WCM) three wheel sensor transponders located in three of
the four wheel wells, an electronic display, and an indicator lamp.
The receiver circuit for the TPM system is integrated into the WCM for non-remote start vehicles. For factory
installed remote start vehicles, the remote start antenna is external to the WCM. The WCM can also include the
Remote Keyless Entry (RKE) receiver, Remote Start (if equipped), and the Sentry Key Immobilizer (SKIM)
receiver. All four receivers share a number of common components. The WCM decodes the RF signals
transmitted by each of the vehicle’s tire pressure sensors. The decoded information is used to determine if
"warning" or "fault" conditions exist within the TPM system.
Upon detection of a warning or fault condition, the WCM will send a request to the module that controls the
indicator lamp (and the text display if equipped with the Premium system) via the vehicle bus system to illuminate
or flash the indicator lamp. Also, upon detection of a warning or fault condition, the electronic display will send a
request to sound the "chime".
The WCM will store all warning and fault conditions, placard pressure values and low-pressure threshold values
(lamp ON and OFF) in memory that can be accessed through diagnostic communication. If new sensors are
introduced to the vehicle, the data stored for the sensor being replaced will be deleted.
The WCM will store all wheel sensor ID’s and locations and faults in memory that can be accessed through
diagnostic communication. All other data values transmitted from each active wheel sensor (not the spare tire)
shall be stored in the WCM memory.
The WCM automatically learns and stores the sensor IDs while driving “within 10 minutes continuously above 15
mph (24 km/h)” after a sensor has been replaced. The learning sequence will initiate when the vehicle has been
stopped for more than 20 minutes.
NOTE: A new sensor ID can also be programmed directly into the WCM by using a RKE-TPM Analyzer in
conjunction with a Scan Tool. Once the new sensor ID has been programmed, the RKE-TPM
Analyzer can be used to update the TPMS by activating the sensor.

OPERATION
BASE TIRE PRESSURE MONITORING
The tire pressure monitoring system (TPMS) is designed to operate without loss of function for all OEM tire
construction for this vehicle. Sensors, mounted to each road wheel as part of the valve stem, transmit an RF
signal indicating their individual pressure to a receiver located in the Wireless Control Module (WCM), commonly
referred to as the Sentry Key Remote Entry Module (SKREEM). On a Domestic vehicle, the TPM sensor operates
on a 315 MHz radio frequency. Export vehicle sensors operate on a 433 MHz radio frequency. These
transmissions occur approximately once every minute at speeds over 15 mph (24 km/h). For more information on
sensors, (Refer to 22 - Tires and Wheels/Tire Pressure Monitoring/SENSOR, Tire Pressure Monitoring (TPM) -
Operation).
If the TPM system detects that the tire pressure in any road tire is going low, beyond the Low Pressure (lamp) ON
threshold (see placard table below), the TPM system will continuously illuminate an indicator lamp. If a system
fault is detected, the indicator lamp will flash on/off for 75 seconds, then remain on solid.
If the WCM detects a warning or fault condition at ignition key "on" it will wait ten seconds +/- 10 % before sending
the first request to illuminate the indicator lamp. This will assure that the display module has concluded its bulb
check period. The display module will request a chime once per ignition cycle for each "warning" or "fault"
condition detected. A "warning" or "fault" condition will remain enabled until the problem causing the condition is
corrected and removed/reset.
The WCM shall continuously monitor for the receipt of tire pressure RF message transmissions from the wheel
sensors during both the ignition key "on" and key "off" cycles. The wheel sensor ID’s and the location of each
sensor (e.g. Tire 1, Tire 2 etc.) are stored in the WCM non-volatile memory during the initial Manufacturing Plant
Process, or during a service procedure, as required.
The TPM System will continue to warn the driver of low tire pressure as long as the condition exists, and will not
turn off the indicator lamp until the tire pressure is at or above the Low Pressure (lamp) OFF threshold (see
placard table below). The system will automatically update and the TPM indicator lamp will extinguish once the
updated tire pressures have been received.
Tire pressure will vary with temperature by about 1 psi (6.9 kPa) for every 12°F (6.5°C). This means that when the
outside temperature decreases, the tire pressure will decrease. Tire pressure should always be set based on cold
inflation tire pressure (placard pressure). This is defined as the tire pressure after a vehicle has not been driven
for more than 3 hours (and in outside ambient temperature). The tire pressure will also increase as the vehicle is
driven; this is normal and there should be no adjustment for this increased pressure. For a system fault, the
system will return to normal once the WCM receives a valid transmission from that sensor location.
PREMIUM TIRE PRESSURE MONITORING
The operation and lamp/chime strategy of the Base Tire Pressure Monitoring System (TPMS) also applies to the
Premium TPMS, but the premium TPMS can display text messages and a tire pressure graphic display on the
information cluster. If a low pressure condition is detected, in addition to a chime and indicator lamp turning ON, a
graphic display of the pressure value(s) with the low tire(s) flashing will appear in the Electronic Vehicle
Information Center (EVIC). Once pressure in the suspect tire(s) raises above the Low Pressure (lamp) OFF
Threshold (see placard table below), the lamp will go out once the WCM receives a valid transmission from the
sensor. If a system fault is detected, in addition to a chime and a indicator lamp flashing, a “Check TPM System”
text message will be displayed in the instrument cluster, and the tire pressure graphic display will have "- -“ in
place of the pressure value. After the flash sequence, the TPM indicator lamp will remain illuminated. The system
will return to normal once the WCM receives a valid transmission from that sensor location.
The Premium TPMS determines the location of the tire pressure sensors by using transponders located in three

of the four wheel wells on the vehicle. A fourth transponder is not necessary in the remaining wheel well due to
the process of elimination theory. Once the system knows the location of the first three sensors, it assumes the
location of the fourth tire pressure sensor, and updates the graphic display when necessary. For more
information, (Refer to 22 - Tires and Wheels/Tire Pressure Monitoring/TRANSPONDER, Tire Pressure Monitoring
(TPM) - Operation).
For both the premium and base TPM, the recommended "Placard Pressure", "Low-pressure Threshold" and
“Hysteresis Pressure Values” for the tires installed on the vehicle, are stored in the WCM non-volatile memory
during the initial Manufacturing Plant Process, or during a service procedure, as required. To determine the
pressure thresholds for a vehicle, refer to the Tire Inflation Pressure (Placard) Label, and then apply the placard
pressure to the following table. The Low Pressure OFF Threshold is defined as the Low Pressure ON Threshold
plus the Hysteresis Pressure Value.
For further information, refer to the Owners Manual or the Appropriate Diagnostic Information.
TPM THRESHOLD PRESSURES
NOTE: To determine the pressure thresholds for a vehicle, refer to the Tire Inflation Pressure (Placard)
Label found on the Driver's B-Pillar, then apply the placard pressure to the following table.



Placard Pressure Low Pressure ON Low Pressure off Threshold (PSI)
Threshold (PSI)
(Cold) (PSI)

28 22 26

29 23 27

30 24 28
31 25 29
32 25 29
33 26 30
34 27 31
35 28 32
36 29 33
37 29 34
38 30 35
39 31 36
40 32 37
41 33 38
42 34 39

43 35 40
44 36 41
45 36 41
46 37 43
47 38 44
48 38 45
49 39 45
50 40 47
51 41 48
55 44 52
60 48 57
65 52 62
70 56 67
75 60 72
80 64 77

hi tatsess

i am just getting ready for a show for launch here in the uk i will pass this information on to the software team and get them to check and test the software, correct if needed maybe some one can contact you about this if you send me a PM with your email or send me a email as well with the car details on vin number and year etc........ also the problem you are having, the american team can contact you direct they maybe be able to help more than me here...... as i am for european cars

thanks john i sent e- mail and also pm ..