TEST 2: Testing The Heater Element's Resistance
After having confirmed that your 1.6L Suzuki Sidekick's front oxygen sensor's heater is being fed power and Ground, the next step is to check that its internal resistance is within specification.
The specification for the front O2 sensor heater on the 1996-1998 1.6L Suzuki Sidekick is 11.7 to 14.3 Ohms (Ω)
NOTE: Just a reminder that the upstream oxygen sensor has to be completely cold before proceeding with this test since the manual calls for the O2 sensor to be at room temperature for the resistance test.
OK, this is what you need to do:
Locate the outer 2 male terminals identified with the numbers 1 and 3 in the illustration above of the O2 sensor connector itself (not the engine wiring harness O2 connector).
With your multimeter in Ohms mode, probe terminals #1 and #3 of the O2 sensor itself.
If all is OK, you should see about 11.7 to 14.3 Ωs on your multimeter.
If the heater element is fried, your multimeter will show an open (usually indicated by the letters OL) or a number over 10 K Ωs.
Let's take a look at your test results:
CASE 1: The front O2 sensor's heater resistance is within specification. This test result tells you that front oxygen sensor's heater is OK.
CASE 2: Your multimeter showed an open circuit (OL). This confirms that the upstream O2 sensor's heater element is fried. Replacing the upstream O2 sensor with a new one will solve the P0135 trouble code lighting up the check engine light (CEL).
Here are some more specifics: Since you have:
- Confirmed that the front O2 sensor's heater element is getting power (TEST 1).
- Confirmed that the front O2 sensor's heater element is getting Ground (TEST 2).
- In this test you have confirmed that the heater element's resistance is out of specification.
Taking all of the above into account you can correctly conclude that the upstream O2 sensor, on your 1.6L Suzuki Sidekick (Geo Tracker), needs to be replaced with a new one.
More 1.6L Suzuki Tutorials
You can find a complete list of tutorials in this index: Suzuki 1.6L Index Of Articles.
Here's a small sample of the 1.6L Suzuki tutorials you'll find in the index:
- How To Test The MAF Sensor (1992-1998 1.6L Sidekick).
- How To Test The Throttle Position Sensor (1996-1998 1.6L Sidekick).
- How To Test The Engine Compression (1.6L Suzuki Sidekick, Geo Tracker).
- 1996-1997 MAF Sensor Wiring Diagram (1.6L Sidekick / Tracker).
If this info saved the day, buy me a beer!