6E–153 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0152 – HO2S Circuit High Voltage Bank 2 Sensor 1
StepNo Ye s Va l u e ( s ) Action
61. Ignition “ON,” engine“OFF.”
2. At Bank 2 HO2S 1 connector (PCM side) jumper
both the HO2S high and low signal circuits (PCM
side) to ground.
3. Using Tech 2, monitor Bank 2 HO2S 1 voltage.
Is Bank 2 HO2S 1 voltage below the specified value?
10 mVGo to Step 7Go to Step 8
71. Disconnect the jumpers to ground from Bank 2
HO2S 1 PCM-side connector.
2. With the HO2S 1 connector disconnected, monitor
Bank 2 HO2S 1 voltage.
Is the Bank 2 HO2S 1 voltage between the specified
values?
425-475 mV
Refer to
Diagnostic
Aids
Go to Step 8
8Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–161 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0172 – Fuel Trim System Rich Bank 1
StepNo Ye s Va l u e ( s ) Action
111. Disconnect the vacuum hose from the fuel pressure
regulator and inspect the hose for the presence of
fuel.
2. If fuel is present in the vacuum hose, replace the
fuel pressure regulator (refer to
Fuel Metering
System
).
Did the fuel pressure regulator require replacement?
—Verify repairGo to Step 12
12Ignition “ON,” engine “OFF,” monitor the TP Angle
display on the Tech 2 while slowly depressing the
accelerator pedal.
Does the TP Angle display increase steadily and
evenly from minimum value at closed throttle to
maximum value at wide-open throttle?
Minimum 0%
Maximum
100%
Go to Step 13Go to Step 18
131. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in “closed loop” while
monitoring the “BANK 1 L.T. FUEL TRIM” and
“BANK 1 S. T. FUEL TRIM” display on the Tech 2.
Did both values change to near the specified value?
0%Go to Step 19Go to Step 14
141. Perform “Fuel System Pressure Test.”
2. If Fuel System Pressure Test isolates a problem,
repair as necessary (refer to
Engine Fuel or Fuel
Metering System
).
Did the Fuel System Pressure Test isolate a problem
requiring repair?
—Verify repairGo to Step 16
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
161. Perform the “Injector Balance Test.”
2. If Injector Balance Test isolates a problem, repair as
necessary (refer to
Fuel Metering System).
Did the Injector Balance Test isolate a problem
requiring repair?
—Verify repair Go to Step 17
171. Remove and visually/physically inspect the Bank 1
HO2S 1 for silicon contamination. This will be
indicated by a powdery white deposit on the portion
of the HO2S that is exposed to the exhaust stream.
2. If contamination is evident on the Bank 1 HO2S 1,
replace the contaminated sensors.
Did the sensor require replacement?
—Verify repair
Refer to
Diagnostic
Aids
181. Check the TP sensor mounting screws and tighten
or replace them as necessary if they are loose or
missing.
2. If the screws are OK, replace the TP sensor.
Is the action complete?
—Verify repair—
19Replace the MAF sensor.
Is the action complete?
—Verify repair—
6E–169 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0175 – Fuel Trim System Rich Bank 2
StepNo Ye s Va l u e ( s ) Action
111. Disconnect the vacuum hose from the fuel pressure
regulator and inspect the hose for the presence of
fuel.
2. If fuel is present in the vacuum hose, replace the
fuel pressure regulator (refer to
Fuel Metering
System
).
Did the fuel pressure regulator require replacement?
—Verify repairGo to Step 12
121. Ignition “ON,” engine “OFF.”
2. Monitor the TP Angle display on the Tech 2 while
slowly depressing the accelerator pedal.
Does the TP Angle display increase steadily and
evenly from minimum value at closed throttle to
maximum value at wide-open throttle?
Minimum 0%
Maximum
100%
Go to Step 13Go to Step 18
131. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in “closed loop” while
monitoring the “BANK 1 L.T. FUEL TRIM” and
“BANK 1 S.T. FUEL TRIM” display on the Tech 2.
Did both values change to near the specified value?
0%Go to Step 19Go to Step 14
141. Perform the “Fuel System Pressure Test.”
2. If Fuel System Pressure Test isolates a problem,
repair as necessary (refer to
Engine Fuel or Fuel
Metering System
).
Did the Fuel System Pressure Test isolate a condition
requiring repair?
—Verify repairGo to Step 16
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
161. Perform the “Injector Balance Test.”
2. If the Injector Balance Test isolates a problem,
repair as necessary (refer to
Fuel Metering
System
).
Did the Injector Balance Test isolate a problem
requiring repair?
—Verify repairGo to Step 17
171. Remove and visually/physically inspect the Bank 2
HO2S 1 for silicon contamination. This will be
indicated by a powdery white deposit on the portion
of the HO2S that is exposed to the exhaust stream.
2. If contamination is evident on the Bank 2 HO2S 1,
replace the contaminated sensor.
Did the sensor require replacement?
—Verify repair
Refer to
Diagnostic
Aids
181. Check the TP sensor mounting screws and tighten
or replace them as necessary if they are loose or
missing.
2. If the screws are OK, replace the TP sensor.
Is the action complete?
—Verify repair—
19Replace the MAF sensor.
Is the action complete?
—Verify repair—
6E–172
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0201 – Injector 1 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 1 (green with white
tracer).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green/white wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–175 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0202 – Injector 2 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 2 (green with orange
tracer).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green/orange wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–178
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0203 – Injector 3 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 3 (green).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–181 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0204 – Injector 4 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 4 (green/red).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green/red wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—
6E–184
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0205 – Injector 5 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 5 (green with black
tracer).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green/black wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—