6E–272
ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Engine runs unevenly at idle. If severe, the engine or
vehicle may shake. Engine idle speed may vary in
RPM. Either condition may be severe enough to stall
the engine.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Go to Step 13Go to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
41. Check the PCM grounds for cleanliness, tightness
and proper routing. 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 5
5Observe the long term fuel trim on Tech 2.
Is the long term fuel trim significantly in the negative
range (rich condition)?
—Go to Step 6Go to Step 7
61. Check items that can cause the engine to run rich.
Refer to
Diagnostic Aids in DTC P0172 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
7Is the long term fuel trim significantly in the positive
range (lean condition)?
—Go to Step 8Go to Step 9
81. Check items that can cause the engine to run lean.
Refer to
Diagnostic Aids in DTC P0171 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Check for incorrect idle speed. Ensure that the
following conditions are present:
The engine is fully warm.
The accessories are “OFF.”
2. Using Tech 2, monitor the IAC position.
Is the IAC position within the specified values?Between 10
and 50
counts
Go to Step 11Go to Step 10
6E–282
ENGINE DRIVEABILITY AND EMISSIONS
Cuts Out, Misses Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Steady pulsation or jerking that follows engine speed;
usually more pronounced as engine load increases.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Go to Step 13Go to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
41. Check the PCM grounds for clearness, tightness
and proper routing. 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 5
5Observe the long term fuel trim on Tech 2.
Is the long term fuel trim significantly in the negative
range (rich condition)?
—Go to Step 6Go to Step 7
61. Check items that can cause the engine to run rich.
Refer to
Diagnostic Aids in DTC P0172 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
7Is the long term fuel trim significantly in the positive
range (lean condition)?
—Go to Step 8Go to Step 9
81. Check items that can cause the engine to run lean.
Refer to
Diagnostic Aids in DTC P0171 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Check for incorrect idle speed. Ensure that the
following conditions are present:
The engine is fully warm.
The accessories are “off.”
2. Using Tech 2, monitor the IAC position.
Is the IAC position within the specified values?Between 5
and 50
counts
Go to Step 11Go to Step 10
6E–286
ENGINE DRIVEABILITY AND EMISSIONS
Hesitation, Sag, Stumble Symptom
StepNo Ye s Va l u e ( s ) Action
101. Check for proper ignition voltage output with spark
tester J 26792 (ST-125). Refer to
Electronic Ignition
System
for the procedure.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11
111. Check for a loose ignition coil ground.
Refer to
Electronic Ignition System.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Check the ignition coils for cracks or carbon
tracking.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
131. Remove spark plugs and check for wet plugs,
cracks, wear, improper gap, burned electrodes, or
heavy deposits. Refer to
Electronic Ignition
System
.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 14
141. Check the PCM grounds for clearness, tightness
and proper routing. 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 15
151. Check the MAF sensor connections.
2. If a problem is found, replace the faulty terminals as
necessary. Refer to
Electrical Diagnosis for wiring
repair procedures.
Was a problem found?
—Verify repairGo to Step 16
161. Visually/physically check vacuum hoses for splits,
kinks, and proper connections and routing as
shown on the “Vehicle Emission Control
Information” label.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 17
6E–335 ENGINE DRIVEABILITY AND EMISSIONS
General Description
General Description (PCM and
Sensors)
58X Reference PCM Input
The powertrain control module (PCM) uses this signal
from the crankshaft position (CKP) sensor to calculate
engine RPM and crankshaft position at all engine speeds.
The PCM also uses the pulses on this circuit to initiate
injector pulses. If the PCM receives no pulses on this
circuit, DTC P0337 will set. The engine will not start and
run without using the 58X reference signal.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning “ON” the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis for A/C wiring
diagrams and diagnosis for the A/C electrical system.
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor provides a signal
used by the powertrain control module (PCM) to calculate
the ignition sequence. The CKP sensor initiates the 58X
reference pulses which the PCM uses to calculate RPM
and crankshaft position.
Refer to
Electronic Ignition System for additional
information.
0013
Camshaft Position (CMP) Sensor and
Signal
The camshaft position (CMP) sensor sends a CMP signal
t o t h e P C M . T h e P C M u s e s t h i s s i g n a l a s a “ s y n c p u l s e ” t otrigger the injectors in the proper sequence. The PCM
uses the CMP signal to indicate the position of the #1
piston during its power stroke. This allows the PCM to
calculate true sequential fuel injection (SFI) mode of
operation. If the PCM detects an incorrect CMP signal
while the engine is running, DTC P0341 will set. If the
CMP signal is lost while the engine is running, the fuel
injection system will shift to a calculated sequential fuel
injection mode based on the last fuel injection pulse, and
the engine will continue to run. As long as the fault is
present, the engine can be restarted. It will run in the
calculated sequential mode with a 1-in-6 chance of the
injector sequence being correct.
Refer to
DTC P0341 for further information.
0014
Engine Coolant Temperature (ECT) Sensor
The engine coolant temperature (ECT) sensor is a
thermistor (a resistor which changes value based on
temperature) mounted in the engine coolant stream. Low
coolant temperature produces a high resistance of
100,000 ohms at –40
C (–40F). High temperature
causes a low resistance of 70 ohms at 130
C (266F).
The PCM supplies a 5-volt signal to the ECT sensor
through resistors in the PCM and measures the voltage.
The signal voltage will be high when the engine is cold and
low when the engine is hot. By measuring the voltage, the
PCM calculates the engine coolant temperature. Engine
coolant temperature affects most of the systems that the
PCM controls.
Tech 2 displays engine coolant temperature in degrees.
After engine start-up, the temperature should rise steadily
to about 85
C (185F). It then stabilizes when the
thermostat opens. If the engine has not been run for
several hours (overnight), the engine coolant
temperature and intake air temperature displays should
be close to each other. A hard fault in the engine coolant
sensor circuit will set DTC P0177 or DTC P0118. An
intermittent fault will set a DTC P1114 or P1115.
6E–349 ENGINE DRIVEABILITY AND EMISSIONS
Damage during re-gapping can happen if the gapping
tool is pushed against the center electrode or the
insulator around it, causing the insulator to crack.
When re-gapping a spark plug, make the adjustment
by bending only the ground side terminal, keeping the
tool clear of other parts.
”Heat shock” breakage in the lower insulator tip
generally occurs during several engine operating
conditions (high speeds or heavy loading) and may be
caused by over-advanced timing or low grade fuels.
Heat shock refers to a rapid increase in the tip
temperature that causes the insulator material to
crack.
Spark plugs with less than the recommended amount of
service can sometimes be cleaned and re-gapped , then
returned to service. However, if there is any doubt about
the serviceability of a spark plug, replace it. Spark plugs
with cracked or broken insulators should always be
replaced.
A/C Clutch Diagnosis
A/C Clutch Circuit Operation
A 12-volt signal is supplied to the A/C request input of the
PCM when the A/C is selected through the A/C control
switch.
The A/C compressor clutch relay is controlled through the
PCM. This allows the PCM to modify the idle air control
position prior to the A/C clutch engagement for better idle
quality. If the engine operating conditions are within their
specified calibrated acceptable ranges, the PCM will
enable the A/C compressor relay. This is done by
providing a ground path for the A/C relay coil within the
PCM. When the A/C compressor relay is enabled,
battery voltage is supplied to the compressor clutch coil.
The PCM will enable the A/C compressor clutch
whenever the engine is running and the A/C has been
requested. The PCM will not enable the A/C compressor
clutch if any of the following conditions are met:
The throttle is greater than 90%.
The engine speed is greater than 6315 RPM.
The ECT is greater than 119C (246F).
The IAT is less than 5C (41F).
The throttle is more than 80% open.
A/C Clutch Circuit Purpose
The A/C compressor operation is controlled by the
powertrain control module (PCM) for the following
reasons:
It improvises idle quality during compressor clutch
engagement.
It improvises wide open throttle (WOT) performance.
It provides A/C compressor protection from operation
with incorrect refrigerant pressures.
The A/C electrical system consists of the following
components:
The A/C control head.
The A/C refrigerant pressure switches.
The A/C compressor clutch.
The A/C compressor clutch relay.
The PCM.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning on the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis for A/C wiring
diagrams and diagnosis for A/C electrical system.
General Description (Exhaust Gas
Recirculation (EGR) System)
EGR Purpose
The exhaust gas recirculation (EGR) system is use to
reduce emission levels of oxides of nitrogen (NOx). NOx
emission levels are caused by a high combustion
temperature. The EGR system lowers the NOx emission
levels by decreasing the combustion temperature.
057RW002
Linear EGR Valve
The main element of the system is the linear EGR valve.
The EGR valve feeds small amounts of exhaust gas back
into the combustion chamber. The fuel/air mixture will be
diluted and combustion temperatures reduced.
Linear EGR Control
The PCM monitors the EGR actual positron and adjusts
the pintle position accordingly. The uses information from
the following sensors to control the pintle position:
Engine coolant temperature (ECT) sensor.
Throttle position (TP) sensor.
Mass air flow (MAF) sensor.
Linear EGR Valve Operation and Results
of Incorrect Operation
The linear EGR valve is designed to accurately supply
EGR to the engine independent of intake manifold
vacuum. The valve controls EGR flow from the exhaust
6E–1 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
4JX1–TC 3.0L ENGINE
DRIVEABILITY AND EMISSIONS
CONTENTS
Specification 6E–7. . . . . . . . . . . . . . . . . . . . . . . . . .
Tightening Specifications 6E–7. . . . . . . . . . . . . . .
Diagrams and Schematics 6E–8. . . . . . . . . . . . . . . .
ECM Wiring Diagram (1 of 6) 6E–8. . . . . . . . . . . .
ECM Wiring Diagram (2 of 6) 6E–9. . . . . . . . . . . .
ECM Wiring Diagram (3 of 6) 6E–10. . . . . . . . . . . .
ECM Wiring Diagram (4 of 6) 6E–11. . . . . . . . . . . .
ECM Wiring Diagram (5 of 6) 6E–12. . . . . . . . . . . .
ECM Wiring Diagram (6 of 6) 6E–13. . . . . . . . . . . .
ECM Pinouts 6E–14. . . . . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector – J1
RED – Upper 6E–14. . . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector – J1
RED – Lower 6E–15. . . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector – J2
BLUE – Upper 6E–16. . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 32-Way Connector – J2
BLUE – Lower 6E–17. . . . . . . . . . . . . . . . . . . . . . . .
ECM Pinout Table, 5-Way Connector – J3 6E–18
Component Locator 6E–19. . . . . . . . . . . . . . . . . . . . .
Sensors and Miscellaneous Component
Locators 6E–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Abbreviations Charts 6E–23. . . . . . . . . . . . . . . . . . . .
Diagnosis 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strategy-Based Diagnostics 6E–24. . . . . . . . . . . . .
Strategy-Based Diagnostics 6E–24. . . . . . . . . . . . .
DTC Stored 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . .
No DTC 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No Matching Symptom 6E–24. . . . . . . . . . . . . . . . .
Intermittents 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . .
No Trouble Found 6E–24. . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E–24. . . . . . . . . . . . . . . .
General Service Information 6E–25. . . . . . . . . . . . . .
Serviceability Issues 6E–25. . . . . . . . . . . . . . . . . . .
Visual/Physical Engine Compartment
Inspection 6E–25. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge of Tools Required 6E–25. . . . . .
Serial Data Communications 6E–25. . . . . . . . . . . . . .
Class II Serial Data Communications 6E–25. . . . .
On-Board Diagnostic (OBD) 6E–25. . . . . . . . . . . . . .
On-Board Diagnostic Tests 6E–25. . . . . . . . . . . . .
Comprehensive Component Monitor
Diagnostic Operation 6E–25. . . . . . . . . . . . . . . . . .
Common OBD Terms 6E–26. . . . . . . . . . . . . . . . . .
The Diagnostic Executive 6E–26. . . . . . . . . . . . . . .
DTC Types 6E–26. . . . . . . . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E–27. . . . . . . . . . . . . . . . Reading Flash Diagnostic Trouble Codes 6E–27.
Reading Diagnostic Trouble Codes Using
a TECH 2 6E–28. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tech 2 Scan Tool 6E–29. . . . . . . . . . . . . . . . . . . . . .
Getting Started 6E–30. . . . . . . . . . . . . . . . . . . . . . . .
DTC Modes 6E–32. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Information Mode 6E–32. . . . . . . . . . . . . . . . .
Injector Test 6E–32. . . . . . . . . . . . . . . . . . . . . . . . . .
EGR Valve Test 6E–32. . . . . . . . . . . . . . . . . . . . . . .
Rail Pressure Control Valve Test 6E–32. . . . . . . . .
Injector Balance Test 6E–32. . . . . . . . . . . . . . . . . . .
Data Programming in Case of ECM Change 6E–32
Rail Pressure Sensor Programming 6E–33. . . . . .
Injector Group Sign Programming
(Injector Change) 6E–33. . . . . . . . . . . . . . . . . . . . .
On-Board Diagnostic (OBD) System Check 6E–35.
Circuit Description 6E–37. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E–37. . . . . . . . . . . . . . . . . . . . . . . .
Engine Control Module ECM Diagnosis 6E–39. . . .
Multiple ECM Information Sensor DTCS Set 6E–39
Circuit Description 6E–39. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E–39. . . . . . . . . . . . . . . . . . . . . . . .
EGR (Exhaust Gas Recirculation) Diagnosis 6E–41
Tech 2 Data Definitions and Ranges 6E–41. . . . . . .
Typical Scan Data Values 6E–41. . . . . . . . . . . . . . . .
Test Conditions 6E–41. . . . . . . . . . . . . . . . . . . . . . . .
4JX1-TC Engine (Automatic and Manual
Transmission) 6E–42. . . . . . . . . . . . . . . . . . . . . . . .
No Malfunction Indicator Lamp (MIL) 6E–44. . . . . . .
Circuit Description 6E–44. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E–44. . . . . . . . . . . . . . . . . . . . . . . .
Malfunction Indicator Lamp (MIL) “ON”
Steady 6E–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit description 6E–47. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E–47. . . . . . . . . . . . . . . . . . . . . . . .
Engine Cranks But Will Not Run 6E–49. . . . . . . . . . .
Circuit Description 6E–49. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 6E–49. . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation (EGR) System
Check 6E–52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–52. . . . . . . . . . . . . . . . . . . . .
ECM Diagnostic Trouble Codes 6E–54. . . . . . . . . . .
ECM Diagnostic Trouble Codes 6E–54. . . . . . . . .
Diagnostic Trouble Code (DTC) P0107
(Flash DTC 34)
MAP Sensor Circuit Low Voltage 6E–56. . . . . . . . . .
6E–8
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagrams and Schematics
ECM Wiring Diagram (1 of 6)
060RW127
6E–9 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
ECM Wiring Diagram (2 of 6)
060RW125