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Home >> Cadillac >> 2006 >> STS Base, 3.6 7, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 15 (Engine Control System - 4.6L (LH2) - DTC P0690 To P2135) >> DTC P1138 or P1158 >> Conditions for Clearing the MIL/DTC

Conditions for Clearing the MIL/DTC

WARNING: This page is about a different variant/trim than selected.
DTC P1138 or P1158

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference: Engine Controls Connector End Views or Engine Control Module Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
  1. Allow the engine to reach normal operating temperature. Refer to Scan Tool Data List .
  2. Quickly cycle the throttle from closed throttle to wide open throttle (WOT), 3 times within 5 seconds while observing the HO2S Bank 1 Sensor 2 or HO2S Bank 2 Sensor 2 parameter, with a scan tool.
  3. Observe the HO2S Bank 1 Sensor 2 or HO2S Bank 2 Sensor 2 parameter with a scan tool.
Does the voltage react instantly when performing the above action?
- Go to Step 4  Go to Step 3 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
- Go to Step 4  Go to Intermittent Conditions
4
  1. Turn OFF the ignition.
  2. Disconnect the affected heated oxygen sensor (HO2S) 2.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the HO2S high signal circuit, on the engine harness, side to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.
Is the voltage more than the specified value?
475 mV Go to Step 7  Go to Step 5 
5
  1. Connect a 3-amp fused jumper wire between the HO2S high signal circuit, on the engine harness side connector, and a good ground.
  2. Observe the affected HO2S parameter with a scan tool.
Is the voltage less than the specified value?
25 mV Go to Step 6  Go to Step 8 
6
  1. Remove the jumper wire from the previous step.
  2. Connect a 3-amp fused jumper wire between the HO2S high signal circuit and the HO2S low signal circuit, on the engine harness side connector.
  3. Observe the affected HO2S parameter with a scan tool.
Is the voltage less then the specified value?
25 mV Go to Step 12  Go to Step 9 
7 Measure the voltage from the HO2S low signal circuit, on the engine harness side connector, to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.
Is the voltage more than the specified value?
50 mV Go to Step 10  Go to Step 11 
8 Test the HO2S high signal circuit for an open or high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 17  Go to Step 14 
9 Test the HO2S low signal circuit for an open or high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 17  Go to Step 14 
10 Test the HO2S low signal circuit for a short to voltage. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 17  Go to Step 14 
11 Test the HO2S high signal circuit for a short to voltage or a short to the heater low control circuit. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 17  Go to Step 14 
12 The HO2S is detecting a rich exhaust condition or may be contaminated. Inspect for one of the following conditions:
  • HO2S connector water intrusion
  • A silicon-contaminated HO2S
  • Fuel-contaminated engine oil
  • Incorrect fuel pressure-Refer to Fuel System Diagnosis .
  • Rich fuel injectors
  • An inaccurate mass air flow (MAF) sensor

Repair any of the above or similar engine conditions, as necessary.
Did you find and correct the condition?
- Go to Step 17  Go to Step 13 
13 Test for shorted terminals and poor connections at the HO2S. Refer to Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 17  Go to Step 15 
14 Test for shorted terminals and poor connections at the engine control module (ECM). 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 17  Go to Step 16 
15 Replace the affected HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .
Did you complete the replacement?
- Go to Step 17  -
16 Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?
- Go to Step 17  -
17
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
- Go to Step 2  Go to Step 18 
18 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?
- Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information System OK