P0137
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2000 Pontiac Grand Prix | Grand Prix VIN W Service Manual | Document ID: 561055
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DTC P0137 HO2S Circuit Low Voltage Sensor 2
Circuit Description
A three-way catalytic converter controls emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas, converting them into harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting NOx to nitrogen. The powertrain control module (PCM) has the ability to monitor this process using the HO2S 1 and the HO2S 2 heated oxygen sensors. The HO2S 1 sensor produces an output signal which indicates the amount of oxygen that is present in the exhaust gas that enters the three-way catalytic converter. The HO2S 2 sensor produces an output signal which indicates the oxygen storage capacity of the catalyst. This in turn indicates the ability of the catalyst to efficiently convert the exhaust gases. If the catalyst is operating efficiently, the HO2S 1 signal will be far more active than the signal produced by the HO2S 2 sensor. If the HO2S 2 signal voltage remains excessively low for an extended time, DTC P0137 will set.
Conditions for Running the DTC
• No TP sensor, EVAP system, misfire, IAT sensor, MAP sensor, fuel trim, fuel injector circuit, EGR Pintle Position, ECT sensor, CKP sensor, or MAF sensor DTCs are present.
• The closed loop commanded air-to-fuel ratio is between 14:5 and 14:8.
• The throttle angle is between 3 percent and 40 percent.
Conditions for Setting the DTC
• HO2S 2 signal voltage remains below 10 mV during normal closed loop operation.
OR
• HO2S 2 signal voltage remains below 600 mV during power enrichment mode fuel control operation.
• VIN K--The condition is present for as long as 4 minutes.
• VIN 1--The condition is present for as long as 2.5 minutes.
Action Taken When the DTC Sets
• The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
• The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
Conditions for Clearing the MIL/DTC
• The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
• The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
• The DTC can be cleared by using a scan tool.
Diagnostic Aids
Inspect for the following conditions:
• Heated oxygen sensor wiring--The sensor pigtail may be mis-positioned and contacting the exhaust system.
• Poor PCM to engine grounds--Refer to Ground Distribution Schematics in Wiring Systems .
• Fuel pressure--A condition which causes a lean exhaust can cause the system to become lean if the fuel pressure is too low. The PCM can compensate for some decrease. However, if fuel pressure is too low, DTC P0137 will set.
• The fuel injectors--Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) .
• Vacuum leaks--Inspect for the following conditions:
- Disconnected or damaged vacuum hoses--Refer to Emission Hose Routing Diagram
- Incorrectly installed or malfunctioning crankcase ventilation valve--Refer to Crankcase Ventilation System Inspection .
- Vacuum leaks at the throttle body, the GR valve, and the intake manifold mounting surfaces.
• Exhaust leaks--An exhaust leak may cause outside air to be pulled into the exhaust gas stream past the HO2S, causing the DTC P0137 to set. Inspect for exhaust leaks near the HO2S 2 sensor.
• The MAF sensor--Disconnect the MAF sensor and see if the condition is corrected. If so, replace MAF sensor. Refer to Mass Airflow Sensor Replacement .
• Fuel contamination--Even small amounts of water can be delivered to the fuel injectors. The water can cause a lean exhaust to be indicated. Excessive alcohol in the fuel can also cause this condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
• Loose terminal connection
- Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
- Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
• Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
• Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
3.DTC P0137 failing during power enrichment operation, when the TP angle is above 60 percent, may indicate a condition described in Diagnostic Aids.
7.When the PCM is replaced, you must program the new PCM.
DTC P0137 - HO2S Circuit Low Voltage Sensor 2 Step
Action
Values
Yes
No
1
Did you perform the Powertrain On Board Diagnostic (OBD) System Check?
--
Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2
Important: During this step, observe all H02S voltage parameters. If all parameters remain below the specified value, refer to Diagnostic Aids.
•With the engine at the normal operating temperature, operate the vehicle within the Conditions For Setting the DTC, as specified in the supporting text.
•Use a scan tool in order to monitor HO2S 2 voltage.
Is the voltage less than the specified value?
10 mV
Go to Step 4
Go to Step 3
3
•Turn ON the ignition, with the engine OFF.
•Review and record the scan tool Failure Records data.
•Operate the vehicle within the Failure Records conditions as noted.
•Use a scan tool in order to monitor the Specific DTC info for DTC P0137 until the DTC P0137 test runs.
Does the DTC reset?
--
Go to Step 4
Go to Diagnostic Aids
4
Disconnect the HO2S 2 and jumper the low circuit on the PCM side to ground.
Does the voltage measure near the specified value?
450 mV
Go to Diagnostic Aids
Go to Step 5
5
Turn OFF the ignition, disconnect the PCM, and test the HO2S 2 signal circuit for a short to ground, or for a short to the sensor ground circuit.
Did you find a condition?
--
Go to Step 6
Go to Step 7
6
Repair the HO2S 2 signal circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
--
Go to Step 8
--
7
Important: You must program the replacement PCM.
Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .
Did you complete the replacement?
--
Go to Step 8
--
8
•Use a scan tool in order to clear the DTCs
•Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK
© 2011 General Motors. All rights reserved.
Service Information
2000 Pontiac Grand Prix | Grand Prix VIN W Service Manual | Document ID: 561055
--------------------------------------------------------------------------------
DTC P0137 HO2S Circuit Low Voltage Sensor 2
Circuit Description
A three-way catalytic converter controls emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas, converting them into harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting NOx to nitrogen. The powertrain control module (PCM) has the ability to monitor this process using the HO2S 1 and the HO2S 2 heated oxygen sensors. The HO2S 1 sensor produces an output signal which indicates the amount of oxygen that is present in the exhaust gas that enters the three-way catalytic converter. The HO2S 2 sensor produces an output signal which indicates the oxygen storage capacity of the catalyst. This in turn indicates the ability of the catalyst to efficiently convert the exhaust gases. If the catalyst is operating efficiently, the HO2S 1 signal will be far more active than the signal produced by the HO2S 2 sensor. If the HO2S 2 signal voltage remains excessively low for an extended time, DTC P0137 will set.
Conditions for Running the DTC
• No TP sensor, EVAP system, misfire, IAT sensor, MAP sensor, fuel trim, fuel injector circuit, EGR Pintle Position, ECT sensor, CKP sensor, or MAF sensor DTCs are present.
• The closed loop commanded air-to-fuel ratio is between 14:5 and 14:8.
• The throttle angle is between 3 percent and 40 percent.
Conditions for Setting the DTC
• HO2S 2 signal voltage remains below 10 mV during normal closed loop operation.
OR
• HO2S 2 signal voltage remains below 600 mV during power enrichment mode fuel control operation.
• VIN K--The condition is present for as long as 4 minutes.
• VIN 1--The condition is present for as long as 2.5 minutes.
Action Taken When the DTC Sets
• The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
• The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
Conditions for Clearing the MIL/DTC
• The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
• The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
• The DTC can be cleared by using a scan tool.
Diagnostic Aids
Inspect for the following conditions:
• Heated oxygen sensor wiring--The sensor pigtail may be mis-positioned and contacting the exhaust system.
• Poor PCM to engine grounds--Refer to Ground Distribution Schematics in Wiring Systems .
• Fuel pressure--A condition which causes a lean exhaust can cause the system to become lean if the fuel pressure is too low. The PCM can compensate for some decrease. However, if fuel pressure is too low, DTC P0137 will set.
• The fuel injectors--Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) .
• Vacuum leaks--Inspect for the following conditions:
- Disconnected or damaged vacuum hoses--Refer to Emission Hose Routing Diagram
- Incorrectly installed or malfunctioning crankcase ventilation valve--Refer to Crankcase Ventilation System Inspection .
- Vacuum leaks at the throttle body, the GR valve, and the intake manifold mounting surfaces.
• Exhaust leaks--An exhaust leak may cause outside air to be pulled into the exhaust gas stream past the HO2S, causing the DTC P0137 to set. Inspect for exhaust leaks near the HO2S 2 sensor.
• The MAF sensor--Disconnect the MAF sensor and see if the condition is corrected. If so, replace MAF sensor. Refer to Mass Airflow Sensor Replacement .
• Fuel contamination--Even small amounts of water can be delivered to the fuel injectors. The water can cause a lean exhaust to be indicated. Excessive alcohol in the fuel can also cause this condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
• Loose terminal connection
- Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
- Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
• Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
• Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
3.DTC P0137 failing during power enrichment operation, when the TP angle is above 60 percent, may indicate a condition described in Diagnostic Aids.
7.When the PCM is replaced, you must program the new PCM.
DTC P0137 - HO2S Circuit Low Voltage Sensor 2 Step
Action
Values
Yes
No
1
Did you perform the Powertrain On Board Diagnostic (OBD) System Check?
--
Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2
Important: During this step, observe all H02S voltage parameters. If all parameters remain below the specified value, refer to Diagnostic Aids.
•With the engine at the normal operating temperature, operate the vehicle within the Conditions For Setting the DTC, as specified in the supporting text.
•Use a scan tool in order to monitor HO2S 2 voltage.
Is the voltage less than the specified value?
10 mV
Go to Step 4
Go to Step 3
3
•Turn ON the ignition, with the engine OFF.
•Review and record the scan tool Failure Records data.
•Operate the vehicle within the Failure Records conditions as noted.
•Use a scan tool in order to monitor the Specific DTC info for DTC P0137 until the DTC P0137 test runs.
Does the DTC reset?
--
Go to Step 4
Go to Diagnostic Aids
4
Disconnect the HO2S 2 and jumper the low circuit on the PCM side to ground.
Does the voltage measure near the specified value?
450 mV
Go to Diagnostic Aids
Go to Step 5
5
Turn OFF the ignition, disconnect the PCM, and test the HO2S 2 signal circuit for a short to ground, or for a short to the sensor ground circuit.
Did you find a condition?
--
Go to Step 6
Go to Step 7
6
Repair the HO2S 2 signal circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
--
Go to Step 8
--
7
Important: You must program the replacement PCM.
Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .
Did you complete the replacement?
--
Go to Step 8
--
8
•Use a scan tool in order to clear the DTCs
•Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK
© 2011 General Motors. All rights reserved.
Is an 02 sim more than just some wires and grounding? Never took mine apart.
Just curious as to how it would go bad? Corrosion?
there are two types of sim's
the older (pre caspers having feds come down on em like a ton of bricks) units that simulated the heater circuit and an alternating 350-650mv signal at ~ 2 hz.
and the newer units which seem to have modifications and for some reason alot of heater circuit failures/etc.
one reason i love the DHP/TT, you no longer need em to pass
just remmeber 99 and older are allowed 2 emiss monitor "not ready"'s and will still pass, 00 and newer are only allowed 1 not ready and will still pass
the older (pre caspers having feds come down on em like a ton of bricks) units that simulated the heater circuit and an alternating 350-650mv signal at ~ 2 hz.
and the newer units which seem to have modifications and for some reason alot of heater circuit failures/etc.
one reason i love the DHP/TT, you no longer need em to pass
just remmeber 99 and older are allowed 2 emiss monitor "not ready"'s and will still pass, 00 and newer are only allowed 1 not ready and will still pass
Owell.When you say older models, what companies used those previously?
And yeah, forgot about the emissions thing. But I'm always afraid that it is just one more thing than needed, and just my luck 2 more will show up on the way to be tested.
i dont know if hpt can but look under history codes and youll have everything triggered even if its past the 50 ignition cycle reset
old models were before caspers got hit by the EPA which was around 2006ish?
a few manufacturers made them, but caspers was one of the biggest and therefore the epa made an example of em
here:
http://www.epa.gov/oecaerth/resources/cases/civil/caa/casper-fcsht.html
old models were before caspers got hit by the EPA which was around 2006ish?
a few manufacturers made them, but caspers was one of the biggest and therefore the epa made an example of em
here:
http://www.epa.gov/oecaerth/resources/cases/civil/caa/casper-fcsht.html
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