6E–3 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0351
Ignition 1 Control Circuit 6E–206. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0352
Ignition 2 Control Circuit 6E–209. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0353
Ignition 3 Control Circuit 6E–212. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0354
Ignition 4 Control Circuit 6E–215. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0355
Ignition 5 Control Circuit 6E–218. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0356
Ignition 6 Control Circuit 6E–221. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0402
EGR Pintle Crank Error 6E–224. . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0404
EGR Open Stuck 6E–226. . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0405
EGR Low Voltage 6E–228. . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0406
EGR High Voltage 6E–231. . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0502
VSS Circuit Low Input 6E–234. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0562
System Voltage Low 6E–237. . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0563
System Voltage High 6E–239. . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0601
PCM Memory 6E–240. . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1154
HO2S Circuit Transition Time Ratio Bank 2
Sensor 1 6E–241. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1171
Fuel System Lean During Acceleration 6E–245. . . .
Diagnostic Trouble Code (DTC) P1380
ABS Rough Road ABS System Fault 6E–248. . . . . .
Diagnostic Trouble Code (DTC) P1404
EGR Closed Stuck 6E–249. . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1508
IAC System Low RPM 6E–251. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1509
IAC System High RPM 6E–254. . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1618
Serial Peripheral Interface (SPI) PCM
Interprocessor Communication Error 6E–257. . . . . .
Diagnostic Trouble Code (DTC) P1625
PCM Unexpected Reset 6E–258. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1640
Driver-1-Input High Voltage 6E–259. . . . . . . . . . . . . .
Symptom Diagnosis 6E–262. . . . . . . . . . . . . . . . . . . . .
Default Matrix Table 6E–288. . . . . . . . . . . . . . . . . . . . .
Camshaft Position (CMP) Sensor 6E–291. . . . . . . . . .
Crankshaft Position (CKP) Sensor 6E–292. . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E–292.
Heated Oxygen Sensor (HO2S) 6E–293. . . . . . . . . . .
Intake Air Temperature (IAT) Sensor 6E–295. . . . . . .
Knock Sensor (KS) 6E–296. . . . . . . . . . . . . . . . . . . . . . Mass Air Flow (MAF) Sensor 6E–297. . . . . . . . . . . . .
Manifold Absolute Pressure (MAP) Sensor 6E–297.
Malfunction Indicator Lamp (MIL) 6E–298. . . . . . . . . .
Powertrain Control Module (PCM) 6E–298. . . . . . . . .
EEPROM 6E–300. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Steering Pressure (PSP) Switch 6E–300
. . . .
Throttle Position (TP) Sensor 6E–301. . . . . . . . . . . . .
Vehicle Speed Sensor (VSS) 6E–302. . . . . . . . . . . . .
Air Cleaner/Air Filter 6E–303. . . . . . . . . . . . . . . . . . . . .
Idle Air Control (IAC) Valve 6E–304. . . . . . . . . . . . . . .
Common Chamber 6E–305. . . . . . . . . . . . . . . . . . . . . .
Accelerator Cable Assembly 6E–305. . . . . . . . . . . . . .
Accelerator Pedal Replacement 6E–308. . . . . . . . . . .
Fuel Filter Cap 6E–310. . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 6E–310. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit 6E–313. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Injectors 6E–314. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pressure Regulator 6E–315. . . . . . . . . . . . . . . . .
Fuel Metering System 6E–317. . . . . . . . . . . . . . . . . . . .
Fuel Pump Assembly 6E–318. . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay 6E–319. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Rail Assembly 6E–319. . . . . . . . . . . . . . . . . . . . . .
Fuel Tank 6E–321. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Body (TB) 6E–323. . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition System 6E–324. . . . . . . . . . . . . . . .
Catalytic Converter 6E–325. . . . . . . . . . . . . . . . . . . . . .
Air Conditioning Relay 6E–325. . . . . . . . . . . . . . . . . . .
EVAP Canister Hoses 6E–326. . . . . . . . . . . . . . . . . . . .
EVAP Canister 6E–326. . . . . . . . . . . . . . . . . . . . . . . . . .
EVAP Canister Purge Solenoid 6E–327. . . . . . . . . . . .
Fuel Tank Vent Valve 6E–328. . . . . . . . . . . . . . . . . . . .
Linear Exhaust Gas Recirculation
(EGR) Valve 6E–328. . . . . . . . . . . . . . . . . . . . . . . . . . .
Positive Crankcase Ventilation (PCV) Valve 6E–329.
Wiring and Connectors 6E–330. . . . . . . . . . . . . . . . . . .
PCM Connectors and Terminals 6E–330. . . . . . . . . . .
Wire Harness Repair: Twisted Shielded
Cable 6E–330. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Twisted Leads 6E–331. . . . . . . . . . . . . . . . . . . . . . . . . .
Weather-Pack Connector 6E–332. . . . . . . . . . . . . . . . .
Com-Pack III 6E–333. . . . . . . . . . . . . . . . . . . . . . . . . . .
Metri-Pack 6E–333. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 6E–335. . . . . . . . . . . . . . . . . . . . .
General Description (PCM and Sensors) 6E–335. . .
58X Reference PCM Input 6E–335. . . . . . . . . . . . . .
A/C Request Signal 6E–335. . . . . . . . . . . . . . . . . . . .
Crankshaft Position (CKP) Sensor 6E–335. . . . . . .
Camshaft Position (CMP) Sensor and
Signal 6E–335. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E–335
Electrically Erasable Programmable Read
Only Memory (EEPROM) 6E–336. . . . . . . . . . . . . .
Fuel Control Heated Oxygen Sensors 6E–336. . . .
Intake Air Temperature (IAT) Sensor 6E–336. . . . .
6E–32
ENGINE DRIVEABILITY AND EMISSIONS
Undercarriage Component Locator
F00RW040
Undercarriage Component Locator Table (Automatic Transmission)
Number
NameLocation
1Fuel Pump AssemblyInstalled in the top of the fuel tank
2Fuel Gauge UnitInstalled in the front edge of the fuel tank, on
the right side
3Fuel FilterLocated along the inside of the right frame rail,
ahead of the rear axle
4Vehicle Speed Sensor (VSS)2WD: Protrudes from the transmission
housing, just ahead of the propeller shaft.
4WD: Protrudes from the rear output shaft
housing of the transfer case.
5Heated Oxygen Sensor (Bank 1, HO2S 1)Threaded into the exhaust pipe ahead of the
right-hand catalytic converter
6Heated Oxygen Sensor (Bank 2, HO2S 1)Threaded into the exhaust pipe ahead the
left-hand catalytic converter
6E–33 ENGINE DRIVEABILITY AND EMISSIONS
Undercarriage Component Locator Table (Manual Transmission)
Number
NameLocation
1Fuel Pump AssemblyInstalled in the top of the fuel tank
2Fuel Gauge UnitInstalled in the front edge of the right frame
rail, ahead of the rear axle
3Fuel FilterLocated along the inside of the right frame rail,
ahead of the rear axle
4Vehicle Speed Sensor (VSS)2WD: Protrudes from the transmission
housing, just ahead of the propeller shaft.
4WD: Protrudes from the rear output shaft
housing of the transfer case.
5Heated Oxygen Sensor (Bank 1, HO2S 1)Threaded into the exhaust pipe ahead of the
right-hand catalytic converter
6Heated Oxygen Sensor (Bank 2, HO2S 1)Threaded into the exhaust pipe ahead of the
left-hand catalytic converter
Fuse and Relay Panel (Underhood Electrical Center)
TS23336
6E–38
ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
OBD Serviceablity Issues
The list of non-vehicle faults that could affect the
performance of the OBD system has been compiled.
These non-vehicle faults vary from environmental
conditions to the quality of fuel used.
The illumination of the MIL (“Check Engine” lamp) due to
a non-vehicle fault could lead to misdiagnosis of the
vehicle, increased warranty expense and customer
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Using fuel with the wrong octane rating for your vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using “premium” gasoline will
improve the performance of your vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel’s ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(“Check Engine” lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (“Check Engine” lamp) to turn on.
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (“Check
Engine” lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (“Check Engine”
lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(“Check Engine” lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a “non-vehicle
fault”, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.Related System Faults
Many of the OBD system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Maintenance Schedule
Refer to the Maintenance Schedule.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:
Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.
Inspect hoses that are difficult to see behind other
components.
Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the “Class II” communication system.
Each bit of information can have one of two lengths: long
or short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait. The most
significant result of this regulation is that it provides Tech 2
manufacturers with the capability to access data from any
make or model vehicle that is sold.
6E–73 ENGINE DRIVEABILITY AND EMISSIONS
Te c h 2
ParameterRefer To Typical Data
Va l u e s
(2500 RPM) Typical Data
Values (IDLE) Units
Displayed Data List
Start-Up ECT
(Engine Coolant
Te m p )EngineDegrees C,
Degrees FDepends on
engine coolant
temperature at
time of start-upDepends on
engine coolant
temperature at
time of start-upGeneral Description and
Operation, Engine Coolant
Temperature (ECT) Sensor
Start-Up IAT
(Intake Air
Te m p )EngineDegrees C,
Degrees FDepends on
intake air
temperature at
time of start-upDepends on
intake air
temperature at
time of start-upGeneral Description and
Operation, Intake Air
Temperature (IAT) Sensor
TP
(Throttle
Position)EnginePercent0
—
General Description and
Operation, Throttle
Position (TP) Sensor;
DTCs: P0121,
P0122,P0123
TP Sensor
(Throttle
Position)EngineVo l t s0.50-0.820.60-1.00General Description and
Operation, Throttle
Position (TP) Sensor;
DTCs: P0121,
P0122,P0123
Catalyst
Protection ModeEngineNo/YesNoNoGeneral Description, Fuel
Metering, catalytic
Converter Protection Mode
Vehicle SpeedEngineMPH /
km/h004L30-E Automatic
Transmission Diagnosis
EVAP Purge
SolenoidEnginePercent6599General Description
VIM SolenoidEngineOn/OffOnOnGeneral Description
Security Wait
TimeEngineActive/Inac
tiveInactiveInactive—
6E–224
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0402 EGR Pintle Crank Error
D06RW106
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if pintle position is stuck open. If the PCM
detects a pintle position signal indicates more than 21.5%
and more than for 625 msec during cranking, the PCM will
set DTC P0402.
Conditions for Setting the DTC
Ignition voltage is between 11 and 16 volts.
Intake Air temp is more than 3C
At Engine revolution less than 600 RPM, EGR pintle
position indicates more than 21.5% and more than for
625 msecs.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.
The PCM will store conditions which were present
w h e n t h e D T C w a s s e t a s F r e e z e F r a m e a n d i n F a i l u r e
Records data.
Conditions for Clearing the MIL/DTC
DTC P0402 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:
Foreign material on EGR valve between pintle and
seat may cause EGR stuck open. Inspect foreign
material in EGR valve.
Excessive carbon deposit may cause unsmooth
operation of EGR valve shaft. Inspect carbon deposit
and clean up inside of carbon deposit.
Poor connection or damaged harness–inspect the
wiring harness for damage If the harness appears to be
OK, observe the EGR actual position display on Tech
2 while moving connectors and wiring harnesses
related to EGR valve. A change in the display will
indicate the location of the fault.
NOTE: If the EGR valve shows signs of excessive heat,
check the exhaust system for blockage (possibly a
plugged catalytic converter) using the “Restricted
Exhaust System Check”.
6E–267 ENGINE DRIVEABILITY AND EMISSIONS
Surges and/or Chuggles Symptom
StepNo Ye s Va l u e ( s ) Action
181. Check the exhaust system for possible restriction:
Inspect the exhaust system for damaged or
collapsed pipes.
Inspect the muffler for heat distress or possible
internal failure.
Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure. Refer to
Restricted
Exhaust System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 19
191. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance
6E–269 ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom
StepNo Ye s Va l u e ( s ) Action
111. Check the PCM grounds for the cleanliness,
tightness and proper locations. Refer to the PCM
wiring diagrams in
Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Check the exhaust system for possible restriction:
Inspect the exhaust system for damaged or
collapsed pipes.
Inspect the muffler for heat distress or possible
internal failure.
Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure. Refer to
Restricted
Exhaust System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
131. Check the torque converter clutch (TCC) for proper
operation. Refer to
4L30-E Transmission
Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 14
141. Check for an engine mechanical problem. Check
for low compression, incorrect or worn camshaft,
loose timing belt, etc. Refer to
Engine Mechanical.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 15
151. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance