Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2004 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

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.

DTC P0135

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check-Engine Controls?	-	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	Start the engine. Allow the engine to idle at operating temperature. Refer to Scan Tool Data List . Observe the HO2S 1 Heater Current parameter with a scan tool. Is the amperage within the specified range?	0.23-0.90 A	Go to Step 3	Go to Step 4
3	Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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	IMPORTANT: Use a known good ground. DO NOT use the HO2S 1 heater low control circuit or the HO2S 1 low signal circuit. Disconnect the heated oxygen sensor (HO2S) 1 connector. Turn ON the ignition, with the engine OFF. Probe the HO2S 1 heater ignition voltage circuit, on the engine harness side, with a test lamp connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?	-	Go to Step 6	Go to Step 5
5	Test the HO2S 1 heater ignition 1 voltage fuse for an open. Refer to Circuit Testing in Wiring Systems. Is the fuse open?	-	Go to Step 11	Go to Step 15
6	Turn OFF the ignition. Connect a test lamp between the HO2S 1 heater ignition voltage circuit and HO2S 1 heater low control circuit, on the engine harness side. Start the engine. Does the test lamp illuminate?	-	Go to Step 7	Go to Step 9
7	Leave the test lamp connected between the HO2S 1 heater ignition voltage circuit and the HO2S 1 heater low control circuit. Turn OFF the ignition. Turn ON the ignition, with the engine OFF. Does the test lamp illuminate?	-	Go to Step 10	Go to Step 8
8	Measure the resistance of the following circuits with a DMM: HO2S 1 heater ignition voltage circuit HO2S 1 heater low control circuit Is the resistance of either circuit more than the specified value?	5 ohm	Go to Step 16	Go to Step 13
9	Test the HO2S 1 heater low control circuit for an open or high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 19	Go to Step 14
10	Test the HO2S 1 heater low control circuit for a short to ground or a short to the HO2S 1 low signal circuit. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 19	Go to Step 14
11	Test the HO2S 1 heater ignition voltage circuit for a short to ground and replace the fuse. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 19	Go to Step 12
12	Test the HO2S 1 heater ignition voltage circuit on the sensor side of the HO2S connector for a short to ground. Refer to Circuit Testing in Wiring Systems. Is the sensor shorted to ground?	-	Go to Step 17	Go to Intermittent Conditions
13	Test for an intermittent and for a poor connection at the harness connector of the HO2S 1. Refer to Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 19	Go to Step 17
14	Test for shorted terminals and for poor connections at the harness connector of the powertrain control module (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 19	Go to Step 18
15	Repair the open or high resistance condition in the HO2S 1 heater ignition voltage circuit. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you complete the repair?	-	Go to Step 19	-
16	Repair the circuit that measured high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you complete the repair?	-	Go to Step 19	-
17	Replace the HO2S 1. Refer to Heated Oxygen Sensor Replacement - Position 1 . Did you complete the replacement?	-	Go to Step 19	-
18	Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?	-	Go to Step 19	Go to Step 2
19	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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 20
20	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List	System OK