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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck C6/C7/C8 🢒 DTC 🢒 DTC 13 Oxygen Sensor Circuit

Object Number: 339433 Size: SF
Engine Controls Components
Cell 20: Sensors
Handling ESD Sensitive Parts Notice

Circuit Description

The ECM supplies a voltage of about 0.45 volt between terminals D7 and D6. (If measured with J 39200 , this may read as low as 0.32 volt.). The oxygen sensor varies the voltage within a range of about 1.0 volt if the exhaust is rich to about 0.10 volt if exhaust is lean.

The sensor is like an open circuit and produces no voltage when it is below 315°C (600°F). An open sensor circuit or cold sensor causes an Open Loop operation.

Conditions for Setting the DTC
    • Engine at normal operating temperature.
    • At least 2 minutes engine time after start.
    • Oxygen sensor signal voltage steady between 0.35 and 0.55 volt.
    • Throttle Position (TP) sensor signal above 4%.
    • All conditions must meet for about 60 seconds.

Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will illuminate. The system will go Open Loop.

Conditions for Clearing the MIL/DTC

The conditions for the fault are no longer present and 50 ignition cycles have passed with no further faults or the ignition switch is turned OFF and the battery feed voltage is removed for 10 seconds.

Diagnostic Aids

Normal scan voltage varies between 100 mV to 999 mV (0.1 and 1.0 volt) while in Closed Loop. DTC 13 sets in 1.0 minute if voltage remains between 0.35 and 0.55 volt, but the system will go to Open Loop in about 15 seconds. Refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

  1. If the conditions for a DTC 13 exist, the system will not go Closed Loop.

    2.

  2. This step determines if the sensor is at fault or if the wiring or ECM is the cause of DTC 13.

    3.

  3. In doing this test, use only a J 39200 . This test checks the continuity of the O2S signal circuit and the O2S ground circuit if the O2S ground circuit is open the ECM voltage on the O2S signal circuit will be over 0.6 volt (600 mV).

DTC 13 Oxygen Sensor (O2S) Circuit (Open Circuit)

Step

Action

Value(s)

Yes

No

1

Did you perform the On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Make sure engine is at the normal operating temperature (the specified value).
  2. Run the engine greater than the specified value for 2 minutes.

Does the scan tool indicate a Closed Loop?

80°C (176°F)

1200 RPM

Go to Diagnostic Aids

Go to Step 3

3

  1. Disconnect the Oxygen Sensor (O2S).
  2. Jumper the Oxygen Sensor signal circuit harness (ECM side) to a ground.

Does the scan tool indicate less than the specified voltage with the engine running?

0.2 V

Go to Step 7

Go to Step 4

4

  1. Remove the jumper.
  2. Turn the ignition ON leaving the engine OFF.
  3. Measure the voltage at the Oxygen Sensor signal circuit connector with a J 39200 DVM.

Is the voltage less than the specified value?

0.3 V

Go to Step 5

Go to Step 8

5
  1. Check for an open Oxygen Sensor signal circuit.
  2. If you find a problem, repair as necessary.

Did you find a problem?

--

Go to Step 13

Go to Step 6

6
  1. Check for a faulty connection at the ECM. Refer to Engine Control Module Diagnosis , or Wiring Repairs .
  2. If you find a problem, repair as necessary.

Did you find a problem?

--

Go to Step 13

Go to Step 12

7
  1. Check for a faulty connection at the O2S harness connector.
  2. If you find a problem, repair as necessary. Refer to Wiring Repairs .

Did you find a problem?

--

Go to Step 13

Go to Step 11

8

Is the voltage greater than the specified value?

0.6 V

Go to Step 9

Go to Step 12

9
  1. Check for an open in the oxygen sensor ground circuit. Refer to Wiring Repairs .
  2. If you find a problem, repair as necessary.

Did you find a problem?

--

Go to Step 13

Go to Step 10

10
  1. Check for a faulty connection at the ECM. Refer to Wiring Repairs , or Engine Control Module Diagnosis .
  2. If you find a problem, repair as necessary.

Did you find a problem?

--

Go to Step 13

Go to Step 12

11

Replace the oxygen sensor. Refer to Oxygen Sensor Replacement

Is the action complete?

--

Go to Step 13

--

12

Replace the ECM. Refer to Engine Control Module Replacement .

Is the action complete?

--

Go to Step 13

--

13
  1. Clear the DTCs. Refer to Conditions f0r Clearing the MIL/DTC.
  2. Start the engine and idle it at the normal operating temperature.
  3. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text.

Did the DTC reset?

--

Go to Step 2

Go to Step 14

14

Are any DTCs stored that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK