Chrysler Sebring 2005 Service Manual page 453

8E - 10 ELECTRONIC CONTROL MODULES
POWERTRAIN CONTROL MODULE (Continued)
OPERATION - SENSOR RETURN - PCM INPUT
The sensor return circuit provides a low electrical
noise ground reference for all of the systems sensors.
The sensor return circuit connects to internal ground
circuits within the Powertrain Control Module
(PCM).
DATA BUS COMMUNICATION RECEIVE - PCM
INPUT
The PCM uses the SCI communication bus to pre-
form engine diagnostics and flash operations. The
transmission side of the PCM uses the SCI commu-
nication bus to flash new software. However, diagnos-
tics is performed via the vehicles J1850 bus for the
transmission side of the PCM.
OPERATION - IGNITION SENSE - PCM INPUT
The ignition sense input informs the Powertrain
Control Module (PCM) that the ignition switch is in
the crank or run position.
PCM REPLACEMENT
DESCRIPTION
U S E THE S CAN TOOL TO REP ROGRAM THE
N EW P CM WITH THE VEHICLES ORIGIN AL
ID EN TIF ICATION N U MB ER (VIN ) AN D THE
VEHICLES ORIGIN AL
S TEP IS N OT D ON E A D IAGN OS TIC TROU B LE
COD E (D TC) MAY B E S ET.
PCM GROUND
Ground is provided through multiple pins of the
PCM connector. Depending on the vehicle there may
be as many as two different ground pins. There are
power grounds and sensor grounds.
The power grounds are used to control the ground
side relays, solenoids, ignition coil or injectors. The
signal ground is used for any input that uses sensor
return for ground, and the ground side of any inter-
nal processing component.
The PCM case is shielded to prevent RFI and EMI.
The PCM case is grounded and must be firmly
attached to a good, clean body ground.
Internally all grounds are connected together, how-
ever there is noise suppression on the sensor ground.
For EMI and RFI protection the housing and cover
are also grounded separately from the ground pins.
OPERATION
5 VOLT SUPPLY - PCM OUTPUT
The PCM supplies 5 volts to the following sensors:
• A/C pressure transducer
• Ambient Temperature sensor
MILEAGE. IF THIS
• Battery temperature
• Camshaft Position Sensor (NGC)
• Crankshaft Position Sensor (NGC)
• Engine coolant temperature sensor
• Inlet Air Temperature Sensor
• Knock sensor
• Linear EGR solenoid (if equipped)
• Manifold absolute pressure sensor
• Oil Pressure Switch
• Throttle position sensor
STANDARD PROCEDURE
STANDARD PROCEDURE - OBTAINING
DIAGNOSTIC TROUBLE CODES
BULB CHECK
Key on: Bulb illuminated until vehicle starts, as
long as all once per trip (readiness) monitors com-
pleted. If monitors have n o t been completed, then:
Key on: bulb check for about 5 to 8 seconds, lamp
then flashes if once per trip (readiness) monitors
have n o t been completed until vehicle is started,
then MIL is extinguished.
OBTAINING DTC'S USING SCAN TOOL
(1) Connect the scan tool to the data link (diagnos-
tic) connector. This connector is located in the pas-
senger compartment; at the lower edge of instrument
panel; near the steering column.
(2) Turn the ignition switch on and access the
"Read Fault" screen.
(3) Record all the DTC's and "freeze frame" infor-
mation shown on the scan tool.
(4) To erase DTC's, use the "Erase Trouble Code"
data screen on the scan tool. D o n o t e ra s e a n y
D TC's u n til p ro ble m s h a v e be e n in v e s tig a te d
a n d re p a irs h a v e be e n p e rfo rm e d .
STANDARD PROCEDURE - PINION FACTOR
SETTING
NOTE: This procedure must be performed if the
PCM has been replaced with a NEW or replacement
unit. Failure to perform this procedure will result in
an inoperative or improperly calibrated speedome-
ter.
The vehicle speed readings for the speedometer are
taken from the output speed sensor. The PCM must
be calibrated to the different combinations of equip-
ment (final drive and tires) available. Pinion Factor
allows the technician to set the Powertrain Control
Module initial setting so that the speedometer read-
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