
(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P0713 Trans Temp Sensor Voltage Too
HighTransmission fluid temperature sensor input above
acceptable voltage. Was MIL code 37.
P0713 (M) Trans Temp Sensor Voltage Too
HighVoltage greater than 3.76 volts (4-speed auto. trans.
only).
P0720 (M) Low Output SPD Sensor RPM,
Above 15 MPHThe relationship between the Output Shaft Speed Sensor
and vehicle speed is not within acceptable limits.
P0720 (M) Low Output Spd Sensor RPM Above
15 mphOutput shaft speed is less than 60 rpm with vehicle speed
above 15 mph (4-speed auto. trans. only).
P0740 (M) Torq Con Clu, No RPM Drop at
LockupRelationship between engine and vehicle speeds
indicated failure of torque convertor clutch lock-up system
(TCC/PTU solenoid)
P0743 (M) Torque Converter Clutch Solenoid/
Trans Relay CircuitsAn open or shorted condition detected in the torque
converter clutch (part throttle unlock) solenoid control
circuit. Shift solenoid C electrical fault - Aisin transmission
P0743 (M) Torque Converter Clutch Solenoid/
Trans Relay CircuitsAn open or shorted condition detected in the torque
converter part throttle unlock solenoid control circuit (3 or
4-speed auto. trans. only).
P0748 (M) Governor Pressur Sol Control/Trans
Relay CircuitsAn open or shorted condition detected in the Governor
Pressure Solenoid circuit or Trans Relay Circuit in JTEC
RE transmissions.
P0748 (M) Governor Pressure Sol Control/Trans
Relay CircuitsAn open or shorted condition detected in the governor
pressure solenoid or relay circuits (4-speed auto. trans.
only).
P0751 (M) O/D Switch Pressed (Lo) More Than
5 MinutesOverdrive override switch input is in a prolonged
depressed state.
P0751 (M) O/D Switch Pressed (LO) More Than
5 MinOverdrive Off switch input too low for more than 5
minutes (4-speed auto. trans. only).
P0753 (M) Trans 3-4 Shift Sol/Trans Relay
CircuitsAn open or shorted condition detected in the overdrive
solenoid control circuit or Trans Relay Circuit in JTEC RE
transmissions. Was MIL code 45.
P0753 (M) Trans 3-4 Shift Sol/Trans Relay
CircuitsAn open or shorted condition detected in the transmission
2-4 shift solenoid circuit (4-speed auto. trans. only).
P0756 AW4 Shift Sol B (2-3) Functional
FailureShift solenoid B (2-3) functional fault - Aisin transmission
P0783 (M) 3-4 Shift Sol, No RPM Drop at
LockupThe overdrive solenoid is unable to engage the gear
change from 3rd gear to the overdrive gear.
P0801 Reverse Gear Lockout Circuit Open
or ShortAn open or shorted condition detected in the transmission
reverse gear lock-out solenoid control circuit.
P0830 Clutch Depressed Switch Circuit Problem detected in clutch switch circuit.
P0833 Clutch Released Switch Circuit Problem detected in clutch switch circuit.
P1110 Decrease Engine Performance Due
To High Intake Air TemperatureIntake manifold air temperature is above the engine
protection limit. Engine power will be derated.
P1180 Decreased Engine Performance Due
To High Injection Pump Fuel TempFuel temperature is above the engine protection limit.
Engine power will be derated.
BR/BEEMISSIONS CONTROL 25 - 9
EMISSIONS CONTROL (Continued)

After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP's solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicated
by a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the Air Fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S sensor output. The programmed
memory acts as a self calibration tool that the engine
controller uses to compensate for variations in engine
specifications, sensor tolerances and engine fatigue
over the life span of the engine. By monitoring the
actual fuel-air ratio with the O2S sensor (short term)
and multiplying that with the program long-term
(adaptive) memory and comparing that to the limit,
it can be determined whether it will pass an emis-
sions test. If a malfunction occurs such that the PCM
cannot maintain the optimum A/F ratio, then the
MIL will be illuminated.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. A meltdown of the ceramic core can
cause a reduction of the exhaust passage. This can
increase vehicle emissions and deteriorate engine
performance, driveability and fuel economy.
The catalyst monitor uses dual oxygen sensors
(O2S's) to monitor the efficiency of the converter. The
dual O2S's sensor strategy is based on the fact that
as a catalyst deteriorates, its oxygen storage capacity
and its efficiency are both reduced. By monitoring
the oxygen storage capacity of a catalyst, its effi-
ciency can be indirectly calculated. The upstream
O2S is used to detect the amount of oxygen in the
exhaust gas before the gas enters the catalytic con-
verter. The PCM calculates the A/F mixture from the
output of the O2S. A low voltage indicates high oxy-
gen content (lean mixture). A high voltage indicates a
low content of oxygen (rich mixture).
When the upstream O2S detects a lean condition,
there is an abundance of oxygen in the exhaust gas.
A functioning converter would store this oxygen so it
can use it for the oxidation of HC and CO. As the
converter absorbs the oxygen, there will be a lack of
oxygen downstream of the converter. The output of
the downstream O2S will indicate limited activity in
this condition.
As the converter loses the ability to store oxygen,
the condition can be detected from the behavior of
the downstream O2S. When the efficiency drops, no
chemical reaction takes place. This means the con-
centration of oxygen will be the same downstream as
upstream. The output voltage of the downstream
O2S copies the voltage of the upstream sensor. The
only difference is a time lag (seen by the PCM)
between the switching of the O2S's.
To monitor the system, the number of lean-to-rich
switches of upstream and downstream O2S's is
counted. The ratio of downstream switches to
upstream switches is used to determine whether the
catalyst is operating properly. An effective catalyst
will have fewer downstream switches than it has
upstream switches i.e., a ratio closer to zero. For a
totally ineffective catalyst, this ratio will be one-to-
one, indicating that no oxidation occurs in the device.
The system must be monitored so that when cata-
lyst efficiency deteriorates and exhaust emissions
increase to over the legal limit, the MIL will be illu-
minated.
BR/BEEMISSIONS CONTROL 25 - 17
EMISSIONS CONTROL (Continued)

SPECIFICATIONS
TORQUE - AIR INJECTION SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Air Pump Filter Housing
Nut18
Air Pump Mounting Bolts 40 30
Air Pump Pulley Mounting
Bolts11 105
One-Way Check Valve to
Catalyst Tube33 25
AIR INJECTION PUMP
DESCRIPTION
The air pump is mounted on the front of the
engine and driven by a belt connected to the crank-
shaft pulley (Fig. 4).
OPERATION
Refer to Air Injection System Description and
Operation for information.
DIAGNOSIS AND TESTING - AIR INJECTION
PUMP
The air injection system and air injection
pump is not completely noiseless.Under normal
conditions, noise rises in pitch as engine speed
increases. To determine if excessive noise is fault of
air injection system, disconnect accessory drive belt
and temporarily operate engine.Do not allow
engine to overheat when operating without
drive belt.
CAUTION: Do not attempt to lubricate the air injec-
tion pump. Oil in the pump will cause rapid deteri-
oration and failure.
Fig. 4 Air Injection Pump MountingÐTypical
1 - PUMP PULLEY
2 - AIR PUMP
3 - AUTOMATIC BELT TENSIONER
4 - PUMP MOUNTING BOLTS (2)
5 - PULLEY BOLTS
25 - 28 AIR INJECTIONBR/BE
AIR INJECTION (Continued)

EXCESSIVE BELT NOISE1. Loose belt or defective automatic
belt tensioner.1. Refer to Cooling System.
2. Seized pump. 2. Replace pump.
EXCESSIVE PUMP NOISE
CHIRPING1. Insufficient break-in. 1. Recheck for noise after 1600 km
(1,000 miles) of operation.
EXCESSIVE PUMP NOISE
CHIRPING, RUMBLING, OR
KNOCKING1. Leak in hose. 1. Locate source of leak using soap
solution and correct.
2. Loose hose. 2. Reassemble and replace or tighten
hose clamp.
3. Hose touching other engine parts. 3. Adjust hose position.
4. Relief valve inoperative. 4. Replace relief valve.
5. Check valve inoperative. 5. Replace check valve.
6. Pump mounting fasteners loose. 6. Tighten mounting screws as
specified.
7. Pump failure. 7. Replace pump.
NO AIR SUPPLY.
ACCELERATE ENGINE TO
1500 RPM AND OBSERVE
AIR FLOW FROM HOSES. IF
FLOW INCREASES AS
RPM'S INCREASE, PUMP IS
FUNCTIONING NORMALLY.
IF NOT, CHECK POSSIBLE
CAUSE.1. Loose drive belt. 1. Refer to Cooling System.
2. Leaks in supply hose. 2. Locate leak and repair or replace as
required.
3. Leak at fitting(s). 3. Tighten and replace clamps.
4. Check valve inoperative. 4. Replace check valve.
5. Plugged inlet air filter (8.0L). 5. Replace filter
REMOVAL
The air injection pump does not have any internal
serviceable parts.
(1) Disconnect both of the hoses (tubes) at the air
injection pump.
(2) Loosen, but do not remove at this time, the
three air pump pulley mounting bolts (Fig. 4).
(3) Relax the automatic belt tensioner and remove
the engine accessory drive belt. Refer to Cooling Sys-
tem. See Belt Removal/Installation.
(4) Remove the three air pump pulley bolts and
remove pulley from pump.
(5) Remove the two air pump mounting bolts (Fig.
4) and remove pump from mounting bracket.
INSTALLATION
(1) Position air injection pump to mounting
bracket.
(2) Install two pump mounting bolts to mounting
bracket. Tighten bolts to 40 N´m (30 ft. lbs.) torque.
(3) Install pump pulley and three mounting bolts.
Tighten bolts finger tight.
(4) Relax tension from automatic belt tensioner
and install drive belt. Refer to Cooling System. See
Belt Removal/Installation.(5) Tighten pump pulley bolts to 11 N´m (105 in.
lbs.) torque.
(6) Install hoses and hose clamps at pump.
AIR PUMP FILTER
REMOVAL
The air filter for the air injection pump is located
inside a housing located in right-front side of engine
compartment (Fig. 3). A rubber hose connects the fil-
ter housing to air injection pump. The filter is used
with 8.0L V-10 engines only.
(1) Remove rubber tubes at filter housing.
(2) Remove filter housing mounting nut and
remove housing.
(3) Remove lid from filter housing (snaps off).
(4) Remove filter from housing.
INSTALLATION
The air filter for the air injection pump is located
inside a housing located in right-front side of engine
compartment (Fig. 3). A rubber hose connects the fil-
ter housing to air injection pump. The filter is used
with 8.0L V-10 engines only.
BR/BEAIR INJECTION 25 - 29
AIR INJECTION PUMP (Continued)

(1) Clean inside of housing and lid before install-
ing new filter.
(2) Install filter into housing.
(3) Install lid to filter housing (snaps on).
(4) Position filter housing to fender.
(5) Install mounting nut and tighten to 11 N´m (8
ft. lbs.) torque.
(6) Install rubber tubes and cap at filter housing.
ONE WAY CHECK VALVE
DESCRIPTION
For air injection systems:A pair of one-way
check valves is used with the air injection system.
The check valves (Fig. 1) are located on each of the
air injection downstream tubes.
OPERATION
Each one-way check valve has a one-way dia-
phragm which prevents hot exhaust gases from back-
ing up into the air injection hose and air injection
pump. The check valve will protect the system if the
air injection pump belt fails, an air hose ruptures or
exhaust system pressure becomes abnormally high.
DIAGNOSIS AND TESTING - ONE-WAY CHECK
VALVE
The one-way check valves are not repairable. To
determine condition of valve, remove the rubber air
tube from the inlet side of each check valve. Start the
engine. If exhaust gas is escaping through the inlet
side of check valve, it must be replaced.
REMOVAL
(1) Remove the hose clamp at inlet side of valve.
(2) Remove hose from valve.
(3) Remove valve from catalyst tube (unscrew).To
prevent damage to catalyst tube, a backup
wrench must be used on the tube.
INSTALLATION
(1) Install valve to catalyst tube. Tighten to 33
N´m (25 ft. lbs.) torque.
(2) Install hose and hose clamp to valve.
25 - 30 AIR INJECTIONBR/BE
AIR PUMP FILTER (Continued)

EVAPORATIVE EMISSIONS
TABLE OF CONTENTS
page page
EVAPORATIVE EMISSIONS
DESCRIPTION...........................31
SPECIFICATIONS........................31
CCV HOSE
DESCRIPTION...........................32
OPERATION.............................32
CRANKCASE VENT HOSE
DESCRIPTION...........................32
EVAP/PURGE SOLENOID
DESCRIPTION...........................32
REMOVAL..............................32
INSTALLATION...........................32
FUEL FILLER CAP
DESCRIPTION...........................33
OPERATION.............................33
REMOVAL..............................33
LEAK DETECTION PUMP
DESCRIPTION...........................33REMOVAL..............................34
INSTALLATION...........................34
PCV FILTER
DESCRIPTION...........................35
P C V VA LV E
DESCRIPTION...........................35
OPERATION.............................35
DIAGNOSIS AND TESTING.................36
PCV VALVE TEST - 3.9/5.2/5.9L ENGINE.....36
VACUUM LINES
DIAGNOSIS AND TESTING.................37
VACUUM SCHEMATICS..................37
VAPOR CANISTER
DESCRIPTION...........................37
OPERATION.............................37
REMOVAL..............................37
INSTALLATION...........................38
EVAPORATIVE EMISSIONS
DESCRIPTION - EVAP SYSTEM
The evaporation control system prevents the emis-
sion of fuel tank vapors into the atmosphere. When
fuel evaporates in the fuel tank, the vapors pass
through vent hoses or tubes into the two charcoal
filled evaporative canisters. The canisters tempo-
rarily hold the vapors. The Powertrain Control Mod-
ule (PCM) allows intake manifold vacuum to draw
vapors into the combustion chambers during certain
operating conditions.
All 3.9L/5.2L/5.9L/8.0L gasoline powered engines
use a duty cycle purge system. The PCM controlsvapor flow by operating the duty cycle EVAP purge
solenoid. Refer to Duty Cycle EVAP Canister Purge
Solenoid for additional information.
When equipped with certain emissions packages, a
Leak Detection Pump (LDP) will be used as part of
the evaporative system. This pump is used as part of
OBD II requirements. Refer to Leak Detection Pump
in this group for additional information.
NOTE: The hoses used in this system are specially
manufactured. If replacement becomes necessary, it
is important to use only fuel resistant hose.
SPECIFICATIONS
TORQUE - EVAP SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
EVAP Canister Mounting Nuts 9 80
Leak Detection Pump Mounting Screws 1 11
Leak Detection Pump Filter Mounting
Bolt765
BR/BEEVAPORATIVE EMISSIONS 25 - 31

REMOVAL
The LDP and LDP filter are attached to a bracket
mounted to the right-inner fender (Fig. 2). The LDP
and LDP filter are replaced (serviced) as one unit.
(1) Carefully remove hose at LDP filter.
(2) Remove LDP filter mounting bolt and remove
from vehicle.
(3) Carefully remove vapor/vacuum lines at LDP.
(4) Disconnect electrical connector at LDP (Fig. 2).
(5) Remove LDP mounting screws and remove
LDP from vehicle.
INSTALLATION
The LDP and LDP filter are attached to a bracket
mounted to the right-inner fender (Fig. 2). The LDP
and LDP filter are replaced (serviced) as one unit.(1) Install LDP to mounting bracket. Tighten
screws to 1 N´m (11 in. lbs.) torque.
(2) Install LDP filter to mounting bracket. Tighten
bolt to 7 N´m (65 in. lbs.) torque.
(3) Carefully install vapor/vacuum lines to LDP,
and install hose to LDP filter.The vapor/vacuum
lines and hoses must be firmly connected.
Check the vapor/vacuum lines at the LDP, LDP
filter and EVAP canister purge solenoid for
damage or leaks. If a leak is present, a Diagnos-
tic Trouble Code (DTC) may be set.
(4) Connect electrical connector to LDP.
Fig. 3 Evaporative System Monitor SchematicÐTypical
1 - DUTY CYCLE PURGE SOLENOID (DCPS) DRIVER
2 - POWERTRAIN CONTROL MODULE (PCM)
3 - 3-PORT SOLENOID DRIVER
4 - REMOTE FILTER
5 - COMBINED CANISTER VENT VALVE & LEAK DETECTION
PUMP
6 - CANISTER7 - TANK ROLLOVER VALVE & VAPOR FLOW CONTROL
ORIFICE
8 - INTAKE MANIFOLD
9 - THROTTLE BODY
10 - DCPS
11 - SWITCH SIGNAL INPUT TO THE PCM
12 - ENGINE VACUUM LINE
25 - 34 EVAPORATIVE EMISSIONSBR/BE
LEAK DETECTION PUMP (Continued)

INSTALLATION
Two EVAP canisters are used. Both canisters are
mounted to a bracket located below rear of vehicle
cab on outside of right frame rail (Fig. 13).(1) Place each canister to mounting bracket (Fig.
13).
(2) Install nuts and tighten to 9 N´m (80 in. lbs.)
torque.
(3) Install fuel tubes/lines to each canister.
25 - 38 EVAPORATIVE EMISSIONSBR/BE
VAPOR CANISTER (Continued)