6E–176
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0203 Injector 3 Control Circuit
D06RW034
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When
the driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the PCM expects to
m o n i t o r o n t h e c i r c u i t , a D T C i s s e t . T h i s D T C i s a l s o s e t i f
an injector driver is shorted to voltage or if there is an open
circuit.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
The engine is turning, determined by the 58X
crankshaft position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded “OFF” or the injector
voltage does not equal 0 volts when the injector is
commanded “ON.”
The above conditions are met for 15 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
DTC P0203 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0203 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0203 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. On the Trooper, the
special 7-way gray connector is located at the front
of the charcoal canister. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 3 is “ON” steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
6E–179 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0204 Injector 4 Control Circuit
D06RW034
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When
the driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the PCM expects to
m o n i t o r o n t h e c i r c u i t , a D T C i s s e t . T h i s D T C i s a l s o s e t i f
an injector driver is shorted to voltage or if there is an open
circuit.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
The engine is turning, determined by the 58X
crankshaft position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded “OFF” or the injector
voltage does not equal 0 volts when the injector is
commanded “ON.”
The above conditions are met for 15 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
DTC P0204 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0204 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0204 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. On the Trooper, the
special 7-way gray connector is located at the front
of the charcoal canister. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 4 is “ON” steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
6E–182
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0205 Injector 5 Control Circuit
D06RW034
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When
the driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. If the voltage is not what the PCM expects to
m o n i t o r o n t h e c i r c u i t , a D T C i s s e t . T h i s D T C i s a l s o s e t i f
an injector driver is shorted to voltage or if there is an open
circuit.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
The engine is turning, determined by the 58X
crankshaft position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded “OFF” or the injector
voltage does not equal 0 volts when the injector is
commanded “ON.”
The above conditions are met for 15 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
DTC P0205 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0205 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0205 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. On the Trooper, the
special 7-way gray connector is located at the front
of the charcoal canister. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 5 is “ON” steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
6E–185 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0206 Injector 6 Control Circuit
D06RW034
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When
the driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the PCM expects to
m o n i t o r o n t h e c i r c u i t , a D T C i s s e t . T h i s D T C i s a l s o s e t i f
an injector driver is shorted to voltage or if there is an open
circuit.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
The engine is turning, determined by 58X crankshaft
position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded “OFF” or the injector
voltage does not equal 0 volts when the injector is
commanded “ON.”
The above conditions are met for 15 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
DTC P0206 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0206 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0206 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. On the Trooper, the
special 7-way gray connector is located at the front
of the charcoal canister. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 6 is “ON” steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
6E–238
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0562 – System Voltage Low
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
2Using a Tech 2, measure the battery voltage at the
battery.
Is the battery voltage greater than the specified value?
11.5 VGo to Step 3
Charge
battery, then
go to
Step 3
31. Using a Tech 2.
2. Select “Ignition Volts” on the Tech 2.
3. Start the engine and raise the engine speed to the
specified value.
4. Load the electrical system by turning on the
headlights, high blower, etc.
Is the ignition voltage approximately equal to the
specified value?
2000 RPM
12.8-14.1 V
Go to Step 4
Go to
Starting/Char
ging
41. Ignition “OFF.”
2. Disconnect the PCM connector at the PCM.
3. Using a DVM, measure the battery voltage at the
PCM connector A-4.
Is it approximately equal to battery voltage?
—
Check for
excessive
current draw
with ignition
“OFF,” engine
“OFF.”
Go to Step 5
51. Check for faulty connections at the PCM harness
terminals.
2. Repair as necessary.
Was a repair necessary?
—Verify repairGo to Step 6
6Check for an open battery feed circuit to the PCM.
Is the action complete?
—Verify repairGo to Step 7
7Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–240
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0601 PCM Memory
Circuit Description
The powertrain control module (PCM) used in this vehicle
utilizes an electrically erasable programmable read-only
memory (EEPROM). The EEPROM contains program
information and the calibrations required for engine,
transmission, and powertrain diagnostics operation.
Unlike the PROM used in past applications, the EEPROM
is not replaceable.
Conditions for Setting the DTC
The PCM detects an internal program fault (check sum
error).
Action Taken When the DTC Sets
The PCM will not illuminate the malfunction indicator
lamp (MIL).
The PCM will store conditions which were present
when the DTC was set in the Failure Records data only.
Conditions for Clearing the MIL/DTC
DTC P0601 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
DTC P0601 indicates that the contents of the
EEPROM have changed since the PCM was
programmed. The only possible repair is PCM
replacement.
DTC P0601 – PCM Memory
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
2Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–262
ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the “On-Board
Diagnostic (OBD) System Check” and verify all of the
following items:
The powertrain control module (PCM) and malfunction
indicator lamp (MIL) (Service Engine Soon lamp) are
operating correctly.
There are no DTC(s) stored.
Tech 2 data is within normal operating range. Refer to
Typical Scan Data Values.
Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:
PCM grounds for cleanliness, tightness and proper
location.
Vacuum hoses for splits, kinks, and proper
connections, as shown on the “Vehicle Emission
Control Information” label. Check thoroughly for any
type of leak or restriction.
Air intake ducts for collapsed or damaged areas.
Air leaks at throttle body mounting area, mass air flow
(MAF) sensor and intake manifold sealing surfaces.
Ignition wires for cracking, hardness, and carbon
tracking.
Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:
Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).
Improperly formed or damaged terminal.
All connector terminals in the problem circuit should be
carefully checked for proper contact tension.
Poor terminal-to-wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a J 39200 Digital Multimeter
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that
there is a fault in the circuit being monitored.
Use Tech 2 to help detect intermittent conditions. Tech 2s
have several features that can be used to locate anintermittent condition. Use the following feature to find
intermittent faults:
Using Tech 2’s “Freeze Frame” buffer or “Failure
Records” buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can be
driven within the conditions that were present when the
DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (Service
Engine Soon lamp) comes on. DTC P0107 should be
stored and kept in memory when the ignition is turned
“OFF.” If not, the PCM is faulty. When this test is
completed, make sure that you clear the DTC P0107 from
memory.
An intermittent MIL (Service Engine Soon lamp) with no
stored DTC may be caused by the following:
Ignition coil shorted to ground and arcing at ignition
wires or plugs.
MIL (Service Engine Soon lamp) wire to PCM shorted
to ground.
Poor PCM grounds. Refer to the PCM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc. Route ignition coil wiring
away from the ignition coils. Check all wires from the
PCM to the ignition coil for poor connections.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
PCM Connector
Symptom
tables.
6E–264
ENGINE DRIVEABILITY AND EMISSIONS
Hard Start Symptom
StepNo Ye s Va l u e ( s ) Action
121. Remove spark plugs. 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 13
131. 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 14
141. Remove the ignition coils and check the ignition
coils for cracks or carbon tracking.
2. If a problem is found, replace affected coil(s) as
necessary.
Was a problem found?
—Verify repairGo to Step 15
151. Check IAC operation. Perform the procedure in the
DTC P0506, Step 6 diagnostic table.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 16
161. Check for the following engine mechanical
problems (refer to
Engine Mechanical):
Low compression
Leaking cylinder head gaskets
Worn or incorrect camshaft
Camshaft drive belt slipped or stripped
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 17
171. 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