6E–239 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0563 System Voltage High
Circuit Description
The powertrain control module (PCM) monitors the
system voltage on the ignition feed terminals to the PCM.
A system voltage DTC will set whenever the voltage is
above a calibrated value.
Conditions for Setting the DTC
Ignition “ON.”
System voltage is above 16 volts for 15 minutes.
Action Taken When the DTC Sets
The PCM will not illuminate the malfunction indicator
lamp (MIL).
The PCM will store as Failure Records only conditions
which were present when the DTC was set. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC
A history DTC P0563 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC P0563 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
If the DTC sets when an accessory is operated, check for
a poor connection or excessive current draw.
DTC P0563 – System Voltage High
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 less than the specified value?
11 . 5 VGo to Step 3Go to Step 4
31. Charge the battery and clean the battery terminals.
2. Clean the battery ground cable connection if
corrosion is indicated.
Is the battery voltage less than the specified value?
11 . 5 V
Replace
battery
Go to Step 4
41. Turn “OFF” all the accessories.
2. Install a Tech 2.
3. Select the ignition voltage parameter on the Tech 2.
4. Start the engine and raise the engine RPM to the
specified value.
Is the voltage more than 2.5 volts greater than the
measurement taken in step 2 or 3?
2000 RPM
Go to
Starting/Char
ging
Go to Step 5
5Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98 model 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–241 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1154 HO2S Circuit Transition Time Ratio
Bank 2 Sensor 1
060RW190
Circuit Description
The powertrain control module (PCM) monitors the
heated oxygen sensor (HO2S) activity for 90 seconds
after “closed loop” and stoichiometric operation have
been enabled. During the monitor period the PCM counts
the number of times that the HO2S responds from
rich-to-lean and from lean-to-rich and adds the amount of
time it took to complete all transitions. With this
information, an average time for all transitions can be
determined. The PCM then divides the rich-to-lean
average by the lean-to-rich average to obtain a ratio. If
the HO2S transition time ratio is not within this range,
DTC P1154 will be set, indicating that the oxygen sensor
is not responding as expected to changes in exhaust
oxygen content.
Conditions for Setting the DTC
No related DTCs.
Engine coolant temperature (ETC) is above 50C
(122F) for automatic transmission; 75C (167F) for
manual transmission.
The engine is operating in “closed loop.”
The engine has been running at least one minute.
Canister purge duty cycle is greater than 2%.
Engine speed is between 1500 RPM and 3000 RPM.
Mass air flow is between 9 g/second and 42 g/second.
Above conditions are present for a 3-second
monitoring period.
90 seconds after “closed loop” and stoichiometric
operation have been enabled, Bank 2 HO2S 1
transition ratio between lean to rich and rich to lean is
less than 0.44 or greater than 3.8.
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.
”Open loop” fuel control will be in effect.
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 P1154 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.
Diagnostic Aids
A multifunction in the HO2S heater ignition feed or ground
circuit may cause a DTC P1154 to set. Check HO2S
heater circuitry for intermittent faults or poor connections.
If connections and wiring are OK and DTC P1154
continues to set, replace the Bank 2 HO2S 1.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
6E–245 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1171 Fuel System Lean During Acceleration
060RW193–1
Circuit Description
The powertrain control module (PCM) internal circuitry
can identify if the vehicle fuel system is capable of
supplying adequate amounts of fuel during heavy
acceleration (power enrichment). The PCM monitors the
voltage of the oxygen sensor during power enrichment.
When a power enrichment mode of operation is
requested during “closed loop” operation (by heavy
acceleration), the PCM will provide more fuel to the
engine. Under these conditions the PCM should detect a
“rich” condition (high oxygen sensor voltage). If this “rich”
exhaust is not detected at this time, a DTC P1171 will set.
A plugged fuel filter, restricted fuel line, restricted in-tank
filter or defective fuel pump can prevent adequate
amounts of fuel from being supplied during power
enrichment mode.
Conditions for Setting the DTC
No related DTCs.
Engine is operating in “closed loop power enrichment”
mode for 3 seconds.
Engine coolant temperature is above 60C (140F).
While in “power enrichment” mode the oxygen sensor
voltage remains below 400 mV for 3 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first 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 P1171 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.
Diagnostic Aids
A restricted fuel filter or fuel line, restricted in-tank filter,
or a defective fuel pomp may supply adequate
6E–247 ENGINE DRIVEABILITY AND EMISSIONS
DTC P1171 – Fuel System Lean During Acceleration
StepNo Ye s Va l u e ( s ) Action
71. Ignition “OFF.”
2. Remove the fuel pump relay and replace it with a
fused jumper which will connect the relay’s battery
terminal to the terminal leading to the fuel pump
fuse.
3. While the fuel pump is operating, use pliers to slowly
close the return line (do not exceed the first
specified value).
Using the pliers to restrict the return line, can the fuel
pressure be manipulated to exceed the second
specified value?
414 kPa
(60 psi)
325 kPa
(46 psi)
Go to
Diagnostic
Aids
Go to Step 8
8Check for:
Faulty fuel pump
Restricted fuel pump strainer (sock)
Incorrect fuel pump
Incorrect fuel being used
Hot fuel
Is the action complete?
—Verify repair—
6E–248
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1380 ABS Rough Road ABS System Fault
Circuit Description
The powertrain control module (PCM) monitors ABS fault
signal. When PCM receives fault signal, PCM will set
DTC P1380.
Conditions for Setting the DTC
Vehicle speed is more than 5 mph.
Load is less than 99%.
Engine revolution is less than 6250 rpm.
PCM receives ABS fault signals from ABS unit.
Ignition on.
Misfire DTCs exist.
100 test failures within 120 test samples.
Action Taken When the DTC Sets
The PCM will store DTC 1380 only, no MIL turn on.
Conditions for Clearing the MIL/DTC
A history DTC P1380 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
DTC 1380 can be cleared by using Tech-2 or
disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:
PCM and ABS communication line short circuit to other
line may cause faulty signal. Inspect communication
line.
Follow ABS ECU diagnosis procedure, refer to ABS
procedure page.
DTC P1380 – ABS Rough Road ABS System Fault
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
21. Ignition “ON,” engine “OFF”, review and record
Tech 2 Failure Records Data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor “Specific DTC” info for DTC
P1380 and Misfire DTCs until the DTC P1380 and
Misfire DTCs test runs. Note the result.
Does the Tech 2 indicates DTC P1380 and Misfire
DTCs failed this ignition?
—
Refer to ABS
diagnosis
After inspect
ABS, unit re-
peat
Step 2
Still problem
exists, go to
Step 3
Clear DTC by
Te c h 2
3Check short circuit among communication line of
PCM/ABS and others.
Was short circuit?
—
Repair wiring
Verify repair
Go to Step 4
4Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–249 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1404 EGR Closed Stuck
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 current pintle zero position is different from
the learned zero position. If the PCM detects a pintle
position signal indicates more than 30 % different
between current zero position and the learned zero
position and more than 5 seconds, and this condition
meet 3 times during trip, then the PCM will set DTC
P1404.
Conditions for Setting the DTC
Ignition voltage is between 11 and 16 volts.
Intake Air temp is more than 3C.
Desire EGR position is 0.
Difference EGR pintle position between current and
the learned zero is more than 30 % last more than 5
seconds, and meet three time to the above condition
during a trip. Then it trigger the PCM lights on.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) after consecutive 2nd trip in which the fault is
detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in Failure
Records data.
Conditions for Clearing the MIL/DTC
DTC P1404 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:
Excessive carbon deposit on EGR valve shaft or/and
foreign material may cause no return to EGR valve
fully seated. Those carbon deposit may occur by
unusual port operation. Remove foreign material
or/and excessive carbon deposit on EGR valve shaft
may make return to EGR valve fully seated.
Poor connection or damaged harness – Inspect the
wiring harness for damage. Same as P1406
description
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
6E–251 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1508 IAC System Low RPM
T321115
Circuit Description
The powertrain control module (PCM) controls engine
idle speed by adjusting the position of the idle air control
(IAC) motor pintle. The IAC is a bi-directional stepper
motor driven by two coils. The PCM applies current to the
IAC coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
PCM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the PCM detects a condition where too low of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the IAC counts, DTC P1508 will set,
indicating a problem with the idle control system.
Conditions for Setting the DTC
No Tech 2 test is being run.
None of these DTCs are set: TP sensor, VSS, ECT,
EGR, fuel system, MAF, MAP, IAT, canister purge,
injector control or ignition control.
Barometric pressure is above 75 kPa.
Engine coolant temperature (ECT) is above 50C
(120
F).
Engine speed is more than 100-200 RPM lower than
desired idle, based upon coolant temperature.
The engine has been running for at least 125 seconds.
Vehicle speed is less than 1 mph.
Canister purge duty cycle is above 10%.
Ignition voltage is between 9.5 volts and 16.7 volts.
The throttle is closed.
Engine speed is lower than desired idle.
All of the above conditions are met for 10 seconds.
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
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
DTC P1508 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:
Poor connection at PCM or IAC motor – Inspect
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire
connection.
Damaged harness – Inspect the wiring for damage.
Restricted air intake system – Check for a possible
collapsed air intake duct, restricted air filter element,
or foreign objects blocking the air intake system.
Throttle body – Check for objects blocking the IAC
passage or throttle bore, excessive deposits in the IAC