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Symptom:
P-0139 1/2 O2S SLOW RESPONSE
When Monitored and Set Condition:
P-0139 1/2 O2S SLOW RESPONSE
When Monitored: With the engine running, engine at normal operating temperature,
ambient air temperature greater than þ7ÉC (20ÉF) and vehicle odometer is greater than
6437 Kilometers (4000 miles).
Set Condition: The Oxygen Sensor Signal voltage does not exceed 0.53 volts and does not
fall below 0.35 volts once during the drive cycle.
POSSIBLE CAUSES
ENGINE MECHANICAL PROBLEM
1/2 O2 SENSOR GROUND CKT HIGH RESISTANCE
1/2 O2 SENSOR GROUND CKT POOR CONNECTION
1/2 O2 SENSOR SIGNAL CKT HIGH RESISTANCE
1/2 O2 SENSOR SIGNAL CKT POOR CONNECTION
1/2 O2 SENSOR SLOW RESPONSE
EXHAUST LEAK
1/2 O2S SLOW RESPONSE DOES NOT REOCCUR
TEST ACTION APPLICABILITY
1 With the DRB, read the DTCs.
Is the GLOBAL GOOD TRIP counter displayed and equal to zero?All
Ye s®Go To 5
No®Go To 2
2 Turn Ignition On (Engine Off).
During the following voltage drop measurement, wiggle wires between O2S Connec-
tor and PCM Connector.
Using a voltmeter, backprobe O2S (Sensor Ground) Circuit between O2S Connector
(Sensor Ground) and PCM Connector (Sensor Ground).
While wiggling wires, is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 3
No®Repair poor connection (high resistance) on O2 Sensor Ground
Circuit.
Perform VERIFICATION TEST VER-5A3.
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Page 77 of 364
Symptom:
P-0140 1/2 O2 SENSOR STAYS AT CENTER
When Monitored and Set Condition:
P-0140 1/2 O2 SENSOR STAYS AT CENTER
When Monitored: With the engine running for more than 2 minutes and engine
temperature greater than 76 degrees C (170 degrees F).
Set Condition: The Upstream Oxygen Sensor Signal voltage is between 0.35 volt and 0.55
volt for 1.5 minutes.
POSSIBLE CAUSES
O2 SENSOR 1/2 GROUND CIRCUIT OPEN
O2 SENSOR 1/2 SIGNAL CIRCUIT OPEN
1/2 O2 SENSOR WIRING HARN INTER DEFECT
1/2 O2 SENSOR WIRING HARN OBS DEFECT
O2 SENSOR 1/2 DEFECTIVE
PCM DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition Off
Start the engine and allow it to reach normal operating temperature.
With the DRB in actuator tests, set RPM to 1500.
In sensors, read the Downstream Oxygen Sensor Level.
Is the Downstream O2 Sensor Level switching?All
Ye s®Go To 2
No®Go To 4
2 Ignition Off
Start the engine and allow it to reach normal operating temperature.
Using the DRB, set the engine speed to 1500 RPM.
With the DRB, read the Downstream O2 Sensor state.
Wiggle Downstream O2 Sensor Connector and Harness.
While wiggling the Harness, monitor the DRB display.
At any time was the Downstream O2 Sensor state locked at center?All
Ye s®Repair the open Harness or Connector that caused the O2 Sensor
state to stay at center.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
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Page 79 of 364
Symptom:
P-0141 1/2 O2S HEATER FAILURE
When Monitored and Set Condition:
P-0141 1/2 O2S HEATER FAILURE
When Monitored: With the ignition key off, after the engine cools down.
Set Condition: No sensor output signal is received when the PCM powers up the sensor
heater.
POSSIBLE CAUSES
1/2 O2 SENSOR CONNECTOR DAMAGED
1/2 O2 SENSOR GND CIRCUIT OPEN
ASD RELAY OUTPUT CIRCUIT OPEN
1/2 O2 SENSOR FAILURE
1/2 O2 SENSOR HEATER ELEMENT FAILURE
1/2 O2S HEATER FAILURE DOES NOT REOCCUR
TEST ACTION APPLICABILITY
1 With the DRB, read the DTCs.
Is the GLOBAL GOOD TRIP counter displayed and equal to zero?All
Ye s®Go To 2
No®Go To 3
2 Turn Ignition On (Engine Off), wait three minutes.
With the DRB, monitor the O2 Sensor voltage for a few minutes until the voltage
stabilizes between .4 and .6 volts.
With the DRB, actuate the O2 Heater test.
Monitor O2 voltage for up to two minutes.
Is the O2 Sensor voltage still between .4 and .6 volts?All
Ye s®Go To 3
No®Go To 4
3 At this time the 1/2 O2S HEATER FAILURE does not exist or is an intermittent
problem.
With the DRB, read the FREEZE FRAME DATA.
With this screen, attempt to duplicate the condition that has set this fault.
While using FREEZE FRAME DATA pay particular attention to the fault setting
conditions, such as speed, temp, load, and map vacuum.
Does the 1/2 O2S HEATER FAILURE reoccur?All
Ye s®Go To 4
No®1/2 O2S Heater failure no longer exists.
Perform VERIFICATION TEST VER-5A3.
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Page 81 of 364
Symptom:
P-0171±1/1 FUEL SYSTEM LEAN
When Monitored and Set Condition:
P-0171±1/1 FUEL SYSTEM LEAN
When Monitored: With the engine running in closed loop mode, the ambient, battery
temperature above Ð5 deg. C (20 deg. F) and altitude below 8000 ft.
Set Condition: If the PCM multiplies short term compensation by long term adaptive and
a certain percentage is exceeded for two trips, a freeze frame is stored, the MIL illuminates
and a trouble code is stored.
POSSIBLE CAUSES
FUEL PUMP MODULE DEFECTIVE
TPS VOLTAGE CHANGE NOT SMOOTH
TPS VOLTAGE <0.92V
FUEL INLET STRAINER PLUGGED
ECT SENSOR DEFECTIVE (OUT OF CALIBRATION)
MAP SENSOR DEFECTIVE (OUT OF CALIBRATION)
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR DEFECTIVE (HIGH)
FUEL FILTER/PRESSURE REGULATOR DEFECTIVE (LOW)
FUEL PUMP CAPACITY (VOLUME) OUT OF SPECS
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRB, read the DTC's.
Is the Global Good Trip Counter displayed and equal to zero for P0171?All
Ye s®Go To 2
No®Go To 13
2 Ignition On, Engine Not Running
With the DRB, read the TPS voltage.
While monitoring the DRB, slowly open and close the Throttle.
Is the voltage change smooth?All
Ye s®Go To 3
No®Replace the Throttle Position Sensor.
Perform Powertrain Verification Test VER-5A.
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Page 85 of 364
Symptom
P0172 -1/1 FUEL SYSTEM RICH
When Monitored and Set Condition:
P0172 -1/1 FUEL SYSTEM RICH
When Monitored: With the engine in closed loop mode, the ambient/battery temperature
above þ5 deg. C (20 deg. F) and altitude below 8000 ft.
Set Condition: If the PCM multiplies short term compensation by long term adaptive and
the result is below a certain value for two trips, a freeze frame is stored, the MIL
illuminates and a trouble code is stored.
POSSIBLE CAUSES
FUEL PUMP MODULE DEFECTIVE
TPS VOLTAGE CHANGE NOT SMOOTH
TPS VOLTAGE <0.92V
FUEL INLET STRAINER PLUGGED
ECT SENSOR DEFECTIVE (OUT OF CALIBRATION)
MAP SENSOR DEFECTIVE (OUT OF CALIBRATION)
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR DEFECTIVE (HIGH)
FUEL FILTER/PRESSURE REGULATOR DEFECTIVE (LOW)
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRB, read the DTC's.
Is the DTC Specific Good Trip Counter displayed and equal to zero?All
Ye s®Go To 2
No®Go To 14
2 Ignition On, Engine Not Running
With the DRB, read the TPS voltage.
While monitoring the DRB, slowly open and close the Throttle.
Is the voltage change smooth?All
Ye s®Go To 3
No®Replace the Throttle Position Sensor.
Perform Powertrain Verification Test VER-5A.
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Page 89 of 364
Symptom:start here
P-0201 INJECTOR #1 CONTROL CIRCUIT
When Monitored and Set Condition:
P-0201 INJECTOR #1 CONTROL CIRCUIT
When Monitored: With battery voltage greater than 12 volts, the auto shutdown relay
energized, injector pulse width less than 10ms, and engine speed less than 3000 rpm.
Set Condition: This trouble code takes .64 to 10.0 seconds to set when no inductive kick
is sensed .18ms after injector turn off, and with no other injectors on.
POSSIBLE CAUSES
ASD RELAY OUTPUT CIRCUIT OPEN
INJECTOR DEFECTIVE
INJECTOR #1 DRIVER CIRCUIT OPEN
INJECTOR #1 DRIVER CIRCUIT SHORTED TO GROUND
POWERTRAIN CONTROL MODULE DEFECTIVE
INJECTOR #1 DRIVER CIRCUIT SHORT TO GROUND
INJECTOR #1 DRIVER CIRCUIT SHORT TO GROUND (PCM)
TEST ACTION APPLICABILITY
1 Ignition Off
Start engine, let idle for at least 20 seconds.
Key on, engine off.
With the DRB, read Trouble Codes.
Is the Global Good Trip counter displayed and equal to zero?All
Ye s®Go To 2
No®Go To 7
2 Ignition Off
Disconnect the Injector #1 Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure resistance of Injector #1.
Is the resistance between 10.0 and 16.0 ohms?All
Ye s®Go To 3
No®Replace the Fuel Injector.
Perform Powertrain Verification Test VER-5A.
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Page 92 of 364
Symptom:
P-0202 INJECTOR #2 CONTROL CIRCUIT
When Monitored and Set Condition:
P-0202 INJECTOR #2 CONTROL CIRCUIT
When Monitored: With battery voltage greater than 12 volts, the auto shutdown relay
energized, injector pulse width less than 10ms, and engine speed less than 3000 rpm.
Set Condition: This trouble code takes .64 to 10.0 seconds to set when no inductive kick
is sensed .18ms after injector turn off, and with no other injectors on.
POSSIBLE CAUSES
ASD RELAY OUTPUT CIRCUIT OPEN
INJECTOR DEFECTIVE
INJECTOR #2 DRIVER CIRCUIT OPEN
INJECTOR #2 DRIVER CIRCUIT SHORTED TO GROUND
PCM DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition Off
Start engine, let idle for at least 20 seconds.
Key on, engine off.
With the DRB, read Trouble Codes.
Is the Global Good Trip counter displayed and equal to zero?All
Ye s®Go To 2
No®Go To 7
2 Ignition Off
Note: It may be necessary to remove the Intake Plenum in the following
steps.
Disconnect the Injector #2 Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure resistance of Injector #2.
Is the resistance between 10.0 and 16.0 ohms?All
Ye s®Go To 3
No®Replace the Fuel Injector.
Perform Powertrain Verification Test VER-5A.
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Symptom:
P-0203 INJECTOR #3 CONTROL CIRCUIT
When Monitored and Set Condition:
P-0203 INJECTOR #3 CONTROL CIRCUIT
When Monitored: With battery voltage greater than 12 volts, the auto shutdown relay
energized, injector pulse width less than 10ms, and engine speed less than 3000 rpm.
Set Condition: This trouble code takes .64 to 10.0 seconds to set when no inductive kick
is sensed .18ms after injector turn off, and with no other injectors on.
POSSIBLE CAUSES
ASD RELAY OUTPUT CIRCUIT OPEN
FUEL INJECTOR #3 DEFECTIVE
INJECTOR #3 DRIVER CIRCUIT OPEN
INJECTOR #3 DRIVER CIRCUIT SHORTED TO GROUND
PCM DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition Off
Start engine, let idle for at least 20 seconds.
Key on, engine off.
With the DRB, read Trouble Codes.
Is the Global Good Trip counter displayed and equal to zero?All
Ye s®Go To 2
No®Go To 7
2 Ignition Off
Note: It may be necessary to remove the Intake Plenum in the following
steps.
Disconnect the Injector #3 Connector.
Note: Check connectors - Clear/repair as necessary.
Using an Ohmmeter, measure the resistance of Injector #3.
Is the resistance between 10.0 and 16.0 ohms?All
Ye s®Go To 3
No®Replace the Fuel Injector.
Perform Powertrain Verification Test VER-5A.
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