DTC P1134 or P1154. GMC Truck GMC C Sierra

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC C Sierra - 2WD 🢒 DTC 🢒 DTC P1134 or P1154

DTC P1134 or P1154 California W/RPO LU3

Circuit Description

The heated oxygen sensor (HO2S) is a sensor designed to create a voltage relative to the oxygen content in the engine exhaust stream. The control module supplies the HO2S with a signal high and low circuits. Ignition voltage and ground are supplied to the HO2S heater by independent circuits. The oxygen content of the exhaust indicates when the engine is operating lean or rich. When the HO2S detects that the engine is operating rich, the signal voltage is high, and decreases the signal voltage as the engine runs leaner. This oscillation above and below the bias voltage, sometimes referred to as activity or switching, can be monitored with the HO2S signal voltage.

The HO2S contains a heater that is necessary in order to quickly warm the sensor to operating temperature. The heater also maintains the operating temperature during extended idle conditions. The HO2S needs to be at a high temperature in order to produce a voltage. When the HO2S reaches operating temperature, the control module monitors the HO2S bias, or reference, voltage. The control module also monitors the HO2S signal voltage for Closed Loop fuel control. During normal Closed Loop fuel control operation, the control module will add fuel, or enrich the mixture, when the HO2S detects a lean exhaust content. The control module will subtract fuel, or lean out the mixture, when the HO2S detects a rich exhaust condition.

This DTC determines if the difference in transition times from lean-to-rich or rich-to-lean has exceeded a maximum ratio. The powertrain control module (PCM) monitors the time needed for the HO2S to transition from more than 600 mV to less than 300 mV and vice versa. If either of these times is longer than the other by a calibrated ratio, this DTC is set.

Conditions for Running the DTC

•	DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0300, P0401, P0404, P0405, P0440, P0442, P0446, P0452, P0453, P1404, or P1441 are not set.

•	The loop status is Closed.

•	The engine run time is more than 160 seconds.

•	The engine speed is between 1,300-3,000 RPM.

•	The engine coolant temperature (ECT) is more than 57°C (135°F).

•	The mass airflow (MAF) sensor is between 20-45 g/s.

•	The throttle position (TP) sensor is more than 5 percent.

•	The ignition 1 signal is between 9-18 volts.

•	The fuel tank level remaining is more than 10 percent.

•	Intrusive tests are not in progress.

•	Scan tool output controls are not active.

•	The evaporative emissions (EVAP) purge solenoid command is more than 1 percent.

•	The above conditions are met for 50 seconds.

Conditions for Setting the DTC

The HO2S transition time ratio is not within a calibrated range.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

•

The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

•	The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

•	A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

•	A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

•	Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

After the ignition is turned ON, the HO2S heater heats up causing the HO2S signal voltage to either increase or decrease. This indicates that the HO2S heater is OK.

If the HO2S voltage is varying outside the specified range, the condition is not present.

If the test lamp illuminates, the low reference circuit between the HO2S and PCM terminal C1-63 is OK and the PCM low reference terminal is OK.

If the voltage is below the specified value, the high signal circuit, the low reference circuit, and the PCM are OK.

The opposite bank HO2S must be disconnected to isolate a short to ground in the HO2S heater ignition 1 voltage circuit.

Resistance within the specified range indicates the HO2S heater is OK.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Important: Allow the engine to cool for one-half hour before proceeding with this diagnostic. This allows the HO2S signal voltage to return to bias voltage, approximately 447 mV.

Install a scan tool.
Turn ON the ignition, with the engine OFF.
Immediately observe the affected HO2S voltage for 2 minutes.

Does the HO2S voltage go from bias voltage to more than or less than the specified range?

300-600 mV

Go to Step 3

Go to Step 5

Start the engine.
Allow the engine to reach operating temperature.
Raise and hold the engine speed at 1,200 RPM for 2 minutes.
Observe the HO2S voltage with a scan tool.

Is the HO2S voltage varying outside the specified range?

350-550 mV

Go to Step 4

Go to Step 5

Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.

Does the DTC fail this ignition?

Go to Step 5

Go to Intermittent Conditions

Are Both DTCs P1134 and P1154 set?

Go to Step 6

Go to Step 7

Turn OFF the ignition.
Disconnect the bank 1 sensor 1 HO2S connector.
Probe the HO2S low reference circuit with a test lamp that is connected to battery positive.

Does the test lamp illuminate?

Go to Step 11

Go to Step 10

Turn OFF the ignition.
Disconnect the affected HO2S connector.
Jumper the HO2S high signal circuit to the low reference circuit.
Turn ON the ignition, with the engine OFF.
Observe the HO2S voltage with a scan tool.

Is the HO2S voltage less than the specified value?

200 mV

Go to Step 11

Go to Step 8

Turn OFF the ignition.
Disconnect the PCM connector containing the HO2S high signal circuit. Refer to Powertrain Control Module Replacement .
Test the HO2S high signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 9

Test for an open between terminal A of the affected sensor harness connector and one of the following PCM terminals:

•	If DTC P1134 is set, use C1-29

•	If DTC P1154 is set, use C1-26

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 18

Disconnect the PCM connector containing the HO2S low reference circuit. Refer to Powertrain Control Module Replacement .
Test the low reference circuit for an open between HO2S bank 1 sensor 1 terminal A and PCM terminal C1-63.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 18

Remove the jumper from the previous step, if applicable.

Is the O2A fuse open?

Go to Step 14

Go to Step 12

Turn ON the ignition, with the engine OFF.
Probe the affected HO2S ignition 1 voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 19

Connect a test lamp between the affected HO2S ignition 1 voltage circuit and the HO2S heater ground circuit.
Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 17

Go to Step 20

Disconnect the opposite bank HO2S pigtail connector.
Test the HO2S ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Replace the O2A fuse.

Did you find and correct a short to ground in the ignition 1 voltage circuit?

Go to Step 23

Go to Step 15

Important: Perform the following test on HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. A condition in either sensor will cause this DTC to set.

Test the HO2S ignition 1 voltage circuit, sensor side, for a short to the HO2S body. Refer to Circuit Testing in Wiring Systems.

Did you find the condition?

Go to Step 21

Go to Step 16

Important: Perform the following test on HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. A condition in either sensor will cause this DTC to set.

Measure the resistance between the HO2S ignition 1 voltage circuit, sensor side, and the HO2S heater ground circuit, sensor side. Refer to Circuit Testing in Wiring Systems.

Does the resistance of either sensor measure above or below the specified range?

2-50 ohms

Go to Step 21

Go to Intermittent Conditions

Inspect for the following conditions that may affect the HO2S operation.

•	The use of incorrect silicon RTV sealant.

•	An engine coolant leak into the combustion chamber.

•	Excessive engine oil consumption.

•	Fuel contamination.

•	An exhaust system leak or restriction.

•	Incorrect fuel pressure.

Did you find and correct the condition?

Go to Step 24

Go to Step 18

Inspect for poor connections at the harness connector of the affected HO2S. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 22

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 23

Repair the open in the ignition 1 voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 24

Repair the open in the HO2S heater ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 24

Replace the affected HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 .

Did you complete the replacement?

Go to Step 24

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

Go to Step 24

Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

Go to Step 25

Go to Step 2

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK

DTC P1134 or P1154 Federal W/RPO L35

Circuit Description

Conditions for Running the DTC

•	DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0200, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0300, P0401, P0404, P0405, P0440, P0442, P0446, P0452, P0453, P1404, or P1441 are not set.

•	The loop status is Closed.

•	The engine run time is more than 160 seconds.

•	The engine speed is between 1,100-3,000 RPM.

•	The engine coolant temperature (ECT) is more than 57°C (135°F).

•	The mass airflow (MAF) sensor is between 15-55 g/s.

•	The throttle position (TP) sensor is more than 5 percent.

•	The ignition 1 signal is between 9-18 volts.

•	The fuel tank level remaining is more than 10 percent.

•	Intrusive tests are not in progress.

•	Scan tool output controls are not active.

•	The evaporative emissions (EVAP) purge solenoid command is more than 1 percent.

•	The above conditions are met for 100 seconds.

Conditions for Setting the DTC

The HO2S transition time ratio is not within a calibrated range.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

•

Conditions for Clearing the MIL/DTC

•	The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

•	A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

•	A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

•	Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Important: Before you service the PCM, remove any debris from the PCM connector surfaces. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

•

Using the Freeze Frame/Failure Records may help to locate an intermittent condition. If you cannot duplicate the DTC, use the information in the Freeze Frame/Failure Records in order to determine how many miles have occurred since the DTC set. You can also use the Fail Counter and the Pass Counter in order to determine how many ignition cycles have occurred in which the diagnostic reported a pass or a fail. In order to isolate when the DTC failed, operate vehicle within the same Freeze Frame conditions that you observed. These conditions include:

•

The RPM

•	The vehicle load

•	The vehicle speed

•	The temperature

•	An oxygen supply inside the HO2S is necessary for proper operation. This oxygen supply is provided through the HO2S wires. Inspect all HO2S wires and connections for breaks or for contamination. Refer to Heated Oxygen Sensor Wiring Repairs in Wiring Systems.

For an intermittent, refer to Symptoms - Engine Controls .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step determines if the condition is present. This test may take minutes for the diagnostic to run. For any test that requires probing the PCM or probing a component harness connector, use the J 35616-A Connector Test Adapter Kit. Using this kit prevents damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.

When DTCs P1134 and P1154 are set at the same time, fuel contamination is likely.

An exhaust leak 152-304 mm (6-12 inches) from the HO2S can cause a DTC to set.

This step tests the HO2S for being tight and determines if the connectors and circuits are OK.

This step tests the integrity of the HO2S low signal circuit to the PCM.

This step tests the integrity of the HO2S high signal circuits to the PCM.

Certain gasket materials are made of room-temperature vulcanizing (RTV) silicon release vapors that can contaminate the HO2S. Silicon in the fuel can also cause silicon contamination. If the sensors appear silicon contaminated, and if all the silicon sealant is a non-silicon base, advise the customer to try a different fuel company. A missing fuel filler restrictor may indicate that the customer has used leaded fuel.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Important: If any DTCs are set, except P1134 or P1154, refer to those DTCs before proceeding with this diagnostic table.

Idle the engine at the normal operating temperature.
Operate the vehicle within the Conditions for Running the DTC in the supporting text.
Monitor the DTC Information option using the scan tool.

Did DTC P1134 or P1154 fail this ignition?

Go to Step 3

Go to Diagnostic Aids

Did both DTC P1134 and P1154 fail this ignition?

Go to Step 8

Go to Step 4

Inspect for an exhaust system leak. Refer to Exhaust Leakage in Engine Exhaust. After you inspect the exhaust system, return to this diagnostic.
If you find an exhaust leak, repair the exhaust leak as necessary.

Did you find and correct the condition?

Go to Step 14

Go to Step 5

Inspect the following items:

•	Ensure that the HO2S is securely installed.

•	Inspect for corrosion on the terminals.

•	Inspect the terminal tension at the HO2S and at the PCM.

•	Inspect for damaged wiring.

Did you find and correct the condition?

Go to Step 14

Go to Step 6

Disconnect the HO2S.
Jumper the HO2S low signal circuit on the PCM side to a known good ground.
Monitor the HO2S voltage on the Engine 1 Data List using the scan tool.

Does the scan tool indicate a voltage that is within the specified range?

350-550 mV

Go to Step 7

Go to Step 10

Jumper the HO2S high and low, PCM side, signal circuits to a battery ground.
Monitor the HO2S voltage using the scan tool.

Does the scan tool indicate a voltage that is less than the specified value?

200 mV

Go to Step 13

Go to Step 9

Important: Determine and correct the cause of the contamination before replacing a sensor. Inspect for the following conditions:

•	Fuel contamination

•	Use of improper RTV sealant

•	Engine oil consumption

•	Coolant consumption

Replace the affected heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 .

Did you complete the action?

Go to Step 14

Remove the jumper wire from the HO2S low signal circuit.
Measure the voltage from the HO2S low signal circuit to a battery ground using the DMM . Refer to Measuring Voltage in Wiring Systems.

Does the DMM indicate a voltage near the specified value?

5 V

Go to Step 12

Go to Step 11

Repair the high signal circuit for a short to ground or a short to voltage. Refer to Wiring Repairs in Wiring Systems.

Did you complete the action?

Go to Step 14

Repair the open HO2S low circuit, or repair the faulty PCM connections. Refer to Wiring Repairs in Wiring Systems.

Did you complete the action?

Go to Step 14

Repair the HO2S high signal circuit for an open, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems.

Did you complete the action?

Go to Step 14

Replace the affected HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 .

Did you complete the action?

Go to Step 14

Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

Go to Step 15

Go to Step 2

With a scan tool observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK