
TABLE OF CONTENTS - Continued
P-1492 BATTERY TEMP SENSOR VOLTAGE TOO HIGH......................18
P-1493 BATTERY TEMP SENSOR VOLTAGE TOO LOW.......................18
P-1594 CHARGING SYSTEM VOLTAGE TOO HIGH...........................19
P-1682 CHARGING SYSTEM VOLTAGE TOO LOW...........................21
* CHECKING CHARGING SYSTEM OPERATION WITH NO DTC'S..............24
DRIVEABILITY
P-0106 BAROMETRIC PRESSURE OUT OF RANGE..........................27
P-0107 MAP SENSOR VOLTAGE TOO LOW.................................30
P-0108 MAP SENSOR VOLTAGE TOO HIGH................................32
P-0112 INTAKE AIR TEMP SENSOR VOLTAGE LOW..........................34
P-0113 INTAKE AIR TEMPERATURE SENSOR VOLT HIGH....................36
P-0117 ECT SENSOR VOLTAGE TOO LOW.................................38
P-0118 ECT SENSOR VOLTAGE TOO HIGH.................................40
P-0121 TPS VOLTAGE DOES NOT AGREE WITH MAP........................42
P-0122 THROTTLE POSITION SENSOR VOLTAGE LOW......................45
P-0123 THROTTLE POSITION SENSOR VOLTAGE HIGH......................48
P-0125 CLOSED LOOP TEMP NOT REACHED...............................51
P-0131 1/1 O2 SENSOR VOLTAGE SHORTED TO GROUND...................53
P-0132 1/1 O2 SENSOR SHORTED TO VOLTAGE............................55
P-0133 1/1 O2S SLOW RESPONSE........................................57
P-0134 1/1 O2 SENSOR STAYS AT CENTER................................60
P-0135 O2S HEATER FAILURE............................................62
P-0137 1/2 O2 SENSOR VOLTAGE SHORTED TO GROUND...................64
P-0138 1/2 O2 SENSOR SHORTED TO VOLTAGE............................66
P-0139 1/2 O2S SLOW RESPONSE........................................68
P-0140 1/2 O2 SENSOR STAYS AT CENTER................................71
P-0141 1/2 O2S HEATER FAILURE........................................73
P-0171±1/1 FUEL SYSTEM LEAN..........................................75
P-0201 INJECTOR #1 CONTROL CIRCUIT..................................83
P-0202 INJECTOR #2 CONTROL CIRCUIT..................................86
P-0203 INJECTOR #3 CONTROL CIRCUIT..................................89
P-0204 INJECTOR #4 CONTROL CIRCUIT..................................92
P-0205 INJECTOR #5 CONTROL CIRCUIT..................................95
P-0206 INJECTOR #6 CONTROL CIRCUIT..................................97
P-0300 MULTIPLE CYLINDER MIS-FIRE...................................100
P-0301 CYLINDER #1 MIS-FIRE..........................................100
P-0302 CYLINDER #2 MIS-FIRE..........................................100
P-0303 CYLINDER #3 MIS-FIRE..........................................100
P-0304 CYLINDER #4 MIS-FIRE..........................................100
P-0305 CYLINDER #5 MIS-FIRE..........................................104
P-0306 CYLINDER #6 MIS-FIRE..........................................104
P-0320 NO CRANK REFERENCE SIGNAL AT PCM..........................108
P-0340 NO CAM SIGNAL AT PCM........................................113
P-0351 IGNITION COIL #1 PRIMARY CIRCUIT..............................122
P-0352 IGNITION COIL #2 PRIMARY CIRCUIT..............................125
P-0353 IGNITION COIL #3 PRIMARY CIRCUIT..............................128
P-0401 EGR SYSTEM FAILURE..........................................131
P-0403 EGR SOLENOID CIRCUIT........................................133
P-0420 1/1 CATALYTIC CONVERTER EFFICIENCY..........................136
P-0441 EVAP PURGE FLOW MONITOR FAILURE...........................138
P-0442 EVAP LEAK MONITOR SMALL LEAK DETECTED.....................140
P-0455 EVAP LEAK MONITOR LARGE LEAK DETECTED.....................140
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TABLE OF CONTENTS - Continued
9.0 CONNECTOR PINOUTS................................................333
A/C COMPRESSOR CLUTCH - BLACK 2 WAY..............................333
AMBIENT TEMPERATURE SENSOR - GRAY 2 WAY.........................333
AMBIENT TEMPERATURE SENSOR (SENSOR SIDE) 2 WAY..................333
BRAKE LAMP SWITCH - GRAY 6 WAY....................................333
BRAKE SHIFT INTERLOCK SOLENOID (EXCEPT BUILT-UP EXPORT)-2WAY ..334
CAMSHAFT POSITION SENSOR - BLACK 3-WAY...........................334
CLOCKSPRING C1 - YELLOW 2 WAY.....................................334
CLOCKSPRING C2 - NATURAL 5 WAY....................................334
CLOCKSPRING C3 - BLACK 2 WAY.......................................335
CLUTCH INTERLOCK SWITCH (MTX) - BLACK 2 WAY.......................335
CLUTCH INTERLOCK SWITCH JUMPER (EATX) - BLACK 2 WAY..............335
CRANKSHAFT POSITION SENSOR - BLACK 3 WAY.........................335
DATA LINK CONNECTOR - BLACK 16 WAY................................336
EGR SOLENOID - GRAY 2 WAY..........................................336
ENGINE COOLANT TEMPERATURE SENSOR - BLACK 2 WAY................336
ENGINE OIL PRESSURE SWITCH - GREEN 2 WAY.........................336
EVAP/PURGE SOLENOID - BLACK 2 WAY.................................337
DUTY CYCLE EVAP/PURGE SOLENOID...................................337
FUEL INJECTOR NO. 1 (2.0L/2.4L) - BLACK 2 WAY..........................337
FUEL INJECTOR NO. 1 (3.3L/3.8L) - BLACK 2 WAY..........................338
FUEL INJECTOR NO. 2 (2.OL/2.4L) - BLACK 2 WAY.........................338
FUEL INJECTOR NO. 2 (3.3L/3.8L) - BLACK 2 WAY..........................338
FUEL INJECTOR NO. 3 (3.3L/3.8L)- BLACK 2 WAY..........................338
FUEL INJECTOR NO. 3 (2.0L/2.4L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 4 (3.3L/3.8L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 4 (2.0L/2.4L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 5 (3.3L/3.8L) - BLACK 2 WAY..........................339
FUEL INJECTOR NO. 6 (3.3L/3.8L) - BLACK 2 WAY..........................340
FUEL TANK MODULE - LIGHT GRAY 4 WAY...............................340
GENERATOR (GENERATOR SIDE).......................................340
GENERATOR - BLACK 3 WAY...........................................340
IDLE AIR CONTROL MOTOR - BLACK 4 WAY..............................341
IGNITION COIL PACK (2.0L/2.4L) - BLACK 3 WAY...........................341
IGNITION COIL PACK (3.3L/3.8L) - BLACK 4 WAY...........................341
INSTRUMENT CLUSTER - BLACK 13 WAY.................................341
INTAKE AIR TEMPERATURE/MANIFOLD ABSOLUTE PRESSURE SENSOR (2.0L) -
GRAY4 WAY..........................................................342
INTAKE AIR TEMPERATURE SENSOR (2.4L) - GRAY 2 WAY..................342
KNOCK SENSOR - GRAY 2 WAY.........................................342
LEAK DETECTION PUMP - LT. GRAY 4 WAY...............................342
MANIFOLD ABSOLUTE PRESSURE SENSOR (2.4L/3.3L/3.8L) - BLACK 3 WAY. . .343
OUTPUT SPEED SENSOR - GRAY 2 WAY.................................343
OXYGEN SENSOR (SENSOR SIDE)......................................343
OXYGEN SENSOR 1/1 UPSTREAM - GRAY 4 WAY..........................343
OXYGEN SENSOR 1/2 DOWNSTREAM - BLACK 4 WAY.....................344
PARK/NEUTRAL POSITION SWITCH (ATX) - BLACK 3 WAY...................344
FUSES...............................................................346
A/C COMPRESSOR CLUTCH RELAY......................................346
AUTOMATIC SHUT DOWN RELAY (GAS)..................................346
CIGAR LIGHTER/ACCESSORY RELAY....................................346
DIESEL POWER RELAY................................................347
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3.2.3 OTHER CONTROLS
CHARGING SYSTEM
The charging system is turned on when the
engine is started and ASD relay energized. When
the ASD relay is on, ASD output voltage is supplied
to the ASD sense circuit at the PCM. This voltage is
connected in some cases, through the PCM and
supplied to one of the generator field terminals
(Gen Source +). All others, the Gen field is con-
nected directly to the ASD output voltage. The
amount of current produced by the generator is
controlled by the Electronic Voltage Regulator
(EVR) circuitry, in the PCM. A battery temperature
sensor, located either in the battery tray, using the
ambient sensor, or in the PCM itself, is used to
sense battery temperature. This temperature along
with sensed line voltage, is used by the PCM to vary
the battery charging rate. This is done by cycling
the ground path to the other generator field termi-
nal (Gen field driver).
SPEED CONTROL SYSTEM
The PCM controls vehicle speed by operation of
the speed control servo vacuum and vent solenoids.
Energizing the vacuum solenoid applies vacuum to
the servo to increase throttle position. Operation of
the vent solenoid slowly releases the vacuum allow-
ing throttle position to decrease. A special dump
solenoid allows immediate release of throttle posi-
tion caused by braking, cruise control switch turned
off, shifting into neutral, excessive RPM (tires spin-
ning) or ignition key off.
3.2.4 PCM OPERATING MODES
As input signals to the powertrain control module
(PCM) change, the PCM adjusts its response to
output devices. For example, the PCM must calcu-
late a different injector pulse width and ignition
timing for idle than it does for wide open throttle.
There are several different modes of operation that
determine how the PCM responds to the various
input signals.
There are two types of engine control operation:
open loopandclosed loop.
In open loop operation, the PCM receives input
signals and responds according to preset program-
ming. Inputs from the heated oxygen sensors are
not monitored.
In closed loop operation, the PCM monitors the
inputs from the heated oxygen sensors. This input
indicates to the PCM whether or not the calculated
injector pulse width results in the ideal air-fuel
ratio of 14.7 parts air to 1 part fuel. By monitoring
the exhaust oxygen content through the oxygen
sensor, the PCM can fine tune injector pulse width.
Fine tuning injector pulse width allows the PCM toachieve the lowest emission levels while maintain-
ing optimum fuel economy.
The engine start-up (crank), engine warm-up,
and wide open throttle modes are open loop modes.
Under most operating conditions, closed loop modes
occur with the engine at operating temperature.
IGNITION SWITCH ON (ENGINE OFF) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
1. The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic
fuel strategy.
2. The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input.
The PCM modifies fuel strategy based on this
input.
When the key is in the ªonº position and the
engine is not running (zero rpm), the auto shut-
down relay and fuel pump relay are not energized.
Therefore, voltage is not supplied to the fuel pump,
ignition coil, and fuel injectors.
Engine Start-up Mode -This is an open loop
mode. The following actions occur when the starter
motor is engaged:
1. The auto shutdown and fuel pump relays are
energized. If the PCM does not receive the cam-
shaft and crankshaft signal within approxi-
mately one second, these relays are de-
energized.
2. The PCM energizes all fuel injectors until it
determines crankshaft position from the cam-
shaft and crankshaft signals. The PCM deter-
mines crankshaft position within one engine
revolution. After the crankshaft position has
been determined, the PCM energizes the fuel
injectors in sequence. The PCM adjusts the in-
jector pulse width and synchronizes the fuel
injectors by controlling the fuel injectors' ground
paths.
3. Once the engine idles within 64 rpm of its target
engine speed, the PCM compares the current
MAP sensor value with the value received dur-
ing the ignition switch on (zero rpm) mode. A
diagnostic trouble code is written to PCM mem-
ory if a minimum difference between the two
values is not found.
Once the auto shutdown and fuel pump relays
have been energized, the PCM determines the fuel
injector pulse width based on the following:
± engine coolant temperature
± manifold absolute pressure
± intake air temperature
± engine revolutions
± throttle position
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The PCM determines the spark advance based on
the following:
± engine coolant temperature
± crankshaft position
± camshaft position
± intake air temperature
± manifold absolute pressure
± throttle position
Engine Warm-Up Mode -This is an open loop-
mode. The PCM adjusts injector pulse width and
controls injector synchronization by controlling the
fuel injectors' ground paths. The PCM adjusts igni-
tion timing and engine idle speed. The PCM adjusts
the idle speed by controlling the idle air control
motor and spark advance.
Cruise or Idle Mode -When the engine is at
normal operating temperature, this is a closed loop
mode.
Acceleration Mode -This is a closed loop mode.
The PCM recognizes an increase in throttle position
and a decrease in manifold vacuum as engine load
increases. In response, the PCM increases the in-
jector pulse width to meet the increased load. The
A/C compressor may be de-energized for a short
period of time.
Deceleration -This is a closed loop mode. The
PCM recognizes a decrease in throttle position and
an increase in manifold vacuum as engine load
decreases. In response, the PCM decreases the
injector pulse width to meet the decreased load.
Full injector shut off may be obtained during high
speed deceleration.
Wide Open Throttle Mode -This is an open
loop mode. The throttle position sensor notifies the
PCM of a wide open throttle condition. Once a wide
open throttle is sensed, the PCM de-energizes the
A/C compressor clutch relay for 15 seconds.
3.2.5 NON-MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems, and conditions even though they could
have malfunctions that result in driveability prob-
lems. A diagnostic code may not be displayed for the
following conditions. However, problems with these
systems may cause a diagnostic code to be displayed
for other systems. For example, a fuel pressure
problem will not register a diagnostic code directly,
but could cause a rich or lean condition. This could
cause an oxygen sensor, fuel system, or misfire
monitor trouble code to be stored in the PCM.
Engine Timing -The PCM cannot detect an
incorrectly indexed timing chain, camshaft
sprocket, or crankshaft sprocket. The PCM also
cannot detect an incorrectly indexed distributor.(*)
Fuel Pressure -Fuel pressure is controlled by
the fuel pressure regulator. The PCM cannot detecta clogged fuel pump inlet filter, clogged in-line filter,
or a pinched fuel supply.(*)
Fuel Injectors -The PCM cannot detect if a fuel
injector is clogged, the pintle is sticking, or the
wrong injectors are installed.(*)
Fuel Requirements -Poor quality gasoline can
cause problems such as hard starting, stalling, and
stumble. Use of methanol-gasoline blends may re-
sult in starting and driveability problems. See indi-
vidual symptoms and their definitions in Section
6.0 (Glossary of Terms)
PCM Grounds -The PCM cannot detect a poor
system ground. However, a diagnostic trouble code
may be stored in the PCM as a result of this
condition.
Throttle Body Air Flow -The PCM cannot
detect a clogged or restricted air cleaner inlet or
filter element.(*)
Exhaust System -The PCM cannot detect a
plugged, restricted, or leaking exhaust system.(*)
Cylinder Compression -The PCM cannot de-
tect uneven, low, or high engine cylinder compres-
sion.(*)
Excessive Oil Consumption -Although the
PCM monitors the exhaust stream oxygen content
through the oxygen sensor when the system is in a
closed loop, it cannot determine excessive oil con-
sumption.
(*)NOTE: ANY OF THESE CONDITIONS
COULD RESULT IN A RICH OR LEAN
CONDITION CAUSING AN OXYGEN SENSOR
TROUBLE CODE TO BE STORED IN THE
PCM, OR THE VEHICLE MAY EXHIBIT ONE
OR MORE OF THE DRIVEABILITY
SYMPTOMS LISTED IN THE TABLE OF
CONTENTS.
3.2.6 SKIS OVERVIEW
The Sentry Key Immobilizer System (SKIS) is an
immobilizer system design to prevent unauthorized
vehicle operation. The system consists of a Sentry
Key Immobilizer Module (SKIM), ignition key(s)
equipped with a transponder chip and engine con-
troller. When the ignition switch is turned on, the
SKIM interrogates the ignition key. If the ignition
key is ``Valid'', the SKIM sends a CCD Bus message
to the engine controller indicating the presence of a
valid igntion key. Upon receiving a ``Valid'' key
signal the PCM will allow the engine to continue to
operate.
3.2.7 SKIM ON-BOARD DIAGNOSTICS
The SKIM has been programmed to transmit and
monitor many different coded messages as well as
CCD Bus messages. This monitoring is called ``On
Board Diagnosis''.
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GENERAL INFORMATION
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applicable. These procedures can be found in ser-
vice manual procedures. Following these proce-
dures is very important to the safety of individuals
performing diagnostic tests.
4.2.2 VEHICLE PREPARATION FOR
TESTING
Make sure the vehicle being tested has a fully
charged battery. If it does not, false diagnostic codes
or error messages may occur.
4.2.3 SERVICING SUB-ASSEMBLIES
Some components of the powertrain system are
intended to be serviced in assembly only. Attempt-
ing to remove or repair certain system sub-
components may result in personal injury and/or
improper system operation. Only those components
with approved repair and installation procedures in
the service manual should be serviced.
4.2.4 DRBIIITSAFETY INFORMATION
WARNING: EXCEEDING THE LIMITS OF THE
DRB MULTIMETER IS DANGEROUS. IT CAN
EXPOSE YOU TO SERIOUS INJURY.
CAREFULLY READ AND UNDERSTAND THE
CAUTIONS AND THE SPECIFICATION
LIMITS.
Follow the vehicle manufacturer 's service specifi-
cations at all times.
²Do not use the DRBIIItif it has been damaged.
²Do not use the test leads if the insulation is
damaged or if metal is exposed.
²To avoid electrical shock, do not touch the test
leads, tips or the circuit being tested.
²Choose the proper range and function for the
measurement. Do not try voltage or current mea-
surements that may exceed the rated capacity.
²Do not exceed the limits shown in the table below:
FUNCTION INPUT LIMIT
Volts 0 - 500 peak volts AC
0 - 500 volts DC
Ohms (resistance)* 0 -1.12 megohms
Frequency Measured
Frequency Generated0-10kHz
Temperature -58 - 1100ÉF
-50 - 600ÉC
* Ohms cannot be measured if voltage is present.
Ohms can be measured only in a non-powered
circuit.
²Voltage between any terminal and ground must
not exceed 500v DC or 500v peak AC.
²Use caution when measuring voltage above 25v
DC or 25v AC.
²The circuit being tested must be protected by a
10A fuse or circuit breaker.
²Use the low current shunt to measure circuits up
to 10A. Use the high current clamp to measure
circuits exceeding 10A.
²When testing for the presence of voltage or cur-
rent, make sure the meter is functioning cor-
rectly. Take a reading of a known voltage or
current before accepting a zero reading.
²When measuring current, connect the meter in
series with the load.
²Disconnect the live test lead before disconnecting
the common test lead.
²When using the meter function, keep the DRB
away from spark plug or coil wires to avoid
measuring error from outside interference.
4.3 WARNINGS AND CAUTIONS
4.3.1 ROAD TEST WARNINGS
Some complaints will require a test drive as part
of the repair verification procedure. The purpose of
the test drive is to try to duplicate the diagnostic
code or symptom condition.
CAUTION: BEFORE ROAD TESTING A
VEHICLE, BE SURE THAT ALL
COMPONENTS ARE REASSEMBLED.
DURING THE TEST DRIVE, DO NOT TRY TO
READ THE DRB SCREEN WHILE IN MOTION.
DO NOT HANG THE DRB FROM THE REAR
VIEW MIRROR OR OPERATE IT YOURSELF.
HAVE AN ASSISTANT AVAILABLE TO
OPERATE THE DRB.
4.3.2 VEHICLE DAMAGE CAUTIONS
Before disconnecting any control module, make
sure the ignition is ªoffº. Failure to do so could
damage the module.
When testing voltage or continuity at any control
module, use the terminal side (not the wire end) of
the connector. Do not probe a wire through the
insulation; this will damage it and eventually cause
it to fail because of corrosion.
Be careful when performing electrical tests so as
to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, a
second code could be set, making diagnosis of the
original problem more difficult.
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GENERAL INFORMATION
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DATA LINK CONNECTOR - BLACK 16 WAYCAV CIRCUIT FUNCTION
1- -
2- -
3 D1 20VT/BR CCD BUS (+)
4 Z2 20BK/LG GROUND
5 Z11 20BK/WT GROUND
6 D20 20LG SCI RECEIVE
7 D21 20PK SCI TRANSMIT
8- -
9- -
10 - -
11 D2 20WT/BK CCD BUS (-)
12 - -
13 - -
14 D6 20PK/LB SCI RECEIVE
15 - -
16 M1 20PK FUSED B(+)
EGR SOLENOID - GRAY 2 WAYCAV CIRCUIT FUNCTION
1 K35 18GY/YL EGR SOLENOID CONTROL
2 F87 18WT/BK FUSED IGNITION SWITCH OUTPUT (ST-RUN)
ENGINE COOLANT TEMPERATURE SENSOR - BLACK 2 WAYCAV CIRCUIT FUNCTION
1 K4 18BK/LB SENSOR GROUND
2 K2 18TN/BK ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
ENGINE OIL PRESSURE SWITCH - GREEN 2 WAYCAV CIRCUIT FUNCTION
1 G6 16GY ENGINE OIL PRESSURE SWITCH SENSE
2- -
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POWERTRAIN CONTROL MODULE C1 - BLACK 40 WAYCAV CIRCUIT FUNCTION
1- -
2 K18 18RD/YL IGNITION COIL NO. 3 DRIVER
3 K17 18DB/TN IGNITION COIL NO. 2 DRIVER
4- -
5 V32 18YL/RD SPEED CONTROL ON/OFF SWITCH SENSE
6 A142 18DG/OR AUTOMATIC SHUT DOWN RELAY OUTPUT
7 K13 18YL/WT FUEL INJECTOR NO. 3 DRIVER
8 K20 18DG GENERATOR FIELD DRIVER (+)
9- -
10 Z12 18BK/TN GROUND
11 K19 18GY/RD IGNITION COIL NO. 1 DRIVER
12 - -
13 K11 18WT/DB FUEL INJECTOR NO. 1 DRIVER
14 K58 18BR/DB FUEL INJECTOR NO. 6 DRIVER
15 K38 18GY FUEL INJECTOR NO. 5 DRIVER
16 K14 18LB/BR FUEL INJECTOR NO. 4 DRIVER
17 K12 18TN/WT FUEL INJECTOR NO. 2 DRIVER
18 - -
19 - -
20 F87 18WT/BK FUSED IGNITION SWITCH OUTPUT (ST-RUN)
21 - -
22 G3 18BK/PK SERVICE ENGINE SOON INDICATOR DRIVER
23 - -
24 - -
25 K42 18DB/LG KNOCK SENSOR SIGNAL
26 K2 18TN/BK ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
27 K127 18BK/OR OXYGEN SENSOR GROUND
28 - -
29 - -
30 K41 18BK/DG OXYGEN SENSOR 1/1 SIGNAL
31 K90 18TN (EXCEPT 3.0L) SMART START RELAY CONTROL
32 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
33 K44 18TN/YL CAMSHAFT POSITION SENSOR SIGNAL
34 - -
35 K22 18OR/DB THROTTLE POSITION SENSOR SIGNAL
36 K1 18DG/RD MANIFOLD ABSOLUTE PRESSURE SENSOR SIGNAL
37 K21 18BK/RD (2.4L) INTAKE AIR TEMPERATURE SIGNAL
38 C103 18DG/LB (EXCEPT
3.0L)A/C SWITCH SIGNAL
39 - -
40 K35 18GY/YL EGR SOLENOID CONTROL
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