DTC P0135 HO2S Heater Performance Sensor 1. Chevrolet Tracker

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 Tracker - 2WD 🢒 DTC 🢒 DTC P0135 HO2S Heater Performance Sensor 1

HO2S Sensors
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The heated oxygen sensors (HO2S) increase the amount of time the sensor spends in closed loop fuel control operation or catalyst monitoring operation. The oxygen sensor heater greatly reduces the amount of time required for the fuel control HO2S (sensor 1) to become active. The oxygen sensor heater is required by the post-catalyst HO2S (sensor 2) in order to maintain the high operating temperatures. The heater helps provide accurate oxygen content readings of the engine exhaust by the HO2S.

Condition for Running the DTC

The ignition is ON or the engine is running.

Conditions for Setting the DTC

•	Current of the HO2S heater is more than 5.3 amps or less than 0.15 amps when the heater is ON.

•	Voltage of the HO2S heater is more than 13.80 volts or lower than 8.7 volts when the heater is ON.

•	Voltage of the HO2S heater is 6 volts, with the heater OFF.

•	One of the above conditions is present for 3 seconds.

Action Taken When the DTC Sets

•	The PCM illuminates the malfunction indicator lamp (MIL) after two consecutive ignition cycles in which the diagnostic runs with the fault active.

•	The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

•	The MIL turns OFF after three consecutively passing trips without a fault present.

•	A History DTC clears after 40 consecutive warm-up cycles without a fault.

•	Use the scan tool Clear DTC Information function or disconnect the PCM battery feed in order to clear the DTC.

Diagnostic Aids

Check for a faulty electrical connection to the PCM.

An intermittent malfunction may be caused by a problem in the HO2S 2 sensor electrical circuit. Inspect the wiring harness and components for any of the following conditions:

•	Backed out terminals

•	Improper mating of terminals

•	Broken electrical connector locks

•	Improperly formed or damaged terminals

•	Faulty terminal to wiring connections

•	Physical damage to the wiring harness

•	A broken wire inside the insulation

•	Corrosion of electrical connections, splices, or terminals

If you cannot duplicate the DTC P0135, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

Test Description

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

The Powertrain OBD System Check prompts the technician to complete some basic checks and to store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

This step will determine if the fault is present.

The HO2S 1 is powered by the IG coil meter fuse located in fuse block 1.

Measures the resistance of the heater portion of the HO2S 1.

This step checks for a short to ground in the HO2S 1 heater circuit. If no problem is found in the HO2S 1 heater circuit, the fault could be a bad (shorted) HO2S 1.

Step	Action	Value(s)	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	Turn ON the ignition, leaving the engine OFF. Use the scan tool Clear Information function. Operate vehicle within the Freeze Frame conditions as observed. Does the scan tool indicate a DTC P0135?	--	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect the HO2S 1 electrical connector. Turn ON the ignition, leaving the engine OFF. Probe the ignition feed circuit, harness side, of the HO2S 1 connector, using a test lamp connected to ground, Did the test lamp illuminate?	--	Go to Step 4	Go to Step 6
4	Turn OFF the ignition. Reconnect the HO2S 1 electrical connector. Disconnect the PCM electrical connectors. Turn ON the ignition, leaving the engine OFF. Measure the voltage from the HO2S 1 heater control circuit, harness side, at the PCM using a DMM. Is the voltage above the specified value?	10 volts	Go to Step 5	Go to Step 7
5	Turn OFF the ignition. Disconnect the HO2S 1 electrical connector. Measure the resistance between the HO2S 1 terminals 3 and 4 at the HO2S 1 pigtail, sensor side, using the DMM. Is the HO2S 1 heater resistance within the specified value?	11.7-14.3 ohms at 20°C (68°F)	Go to Step 12	Go to Step 11
6	Inspect the fuse in the fuse block. Is the fuse blown?	--	Go to Step 8	Go to Step 9
7	Check the HO2S 1 heater control circuit for an open circuit or a short to ground. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Was a repair necessary?	--	Go to Step 13	Go to Step 10
8	Replace the faulty fuse and check the ignition feed circuit for a short to ground. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Was a repair necessary?	--	Go to Step 13	Go to Step 11
9	Check for an open in the ignition feed circuit. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Is the action complete?	--	Go to Step 13	--
10	Check the connections at the HO2S 1 connector. Repair as necessary. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Was a repair necessary?	--	Go to Step 13	Go to Step 11
11	Replace the HO2S 1. Refer to Heated Oxygen Sensor Replacement . Is the action complete?	--	Go to Step 13	--
12	Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete?	--	Go to Step 13	--
13	Perform the scan tool Clear DTC Information function and road test the vehicle within the Freeze Frame conditions that set the DTC. Review the scan tool data. Check for DTCs. The repair is complete if no DTCs are stored. Are any DTCs displayed on the scan tool?	--	Go to Diagnostic Trouble Code (DTC) List	System OK