2002 Chevy Tracker O2 heater sensors code
#11
I checked the pins as you wrote and all things turned out good.. My son had a relay tester that he never used and I tested it and the relay was good. So I went under the car expecting the O2 connections were under there for the downstream O2's. Nope it looks like the go up in back of the engine where the upstream connectors are.
I found this pic. The tan ones are the upstream, but I believe the darker one aside of the one on the right is a downstream, but I'm not sure. I couldn't make out where the downstream wires came up. One Youtube video said the Drivers side downstream is under the front drivers seat. I can't seem to find any good info on the web.
I found this pic. The tan ones are the upstream, but I believe the darker one aside of the one on the right is a downstream, but I'm not sure. I couldn't make out where the downstream wires came up. One Youtube video said the Drivers side downstream is under the front drivers seat. I can't seem to find any good info on the web.
Last edited by hlg1111; May 17th, 2020 at 5:55 PM.
#12
That is a great pic. I have added to it and am reposting it.
All four O2 connectors are shown. B1S2 is shown unplugged so you see the plug and the jack. They are hard to reach.
You need someone with small arms and strong fingers to undo them. The EGR pipe on the passenger side makes the
bank 2 connectors really hard to reach. Use a mirror and flashlight to see how the plugs unlock. Do the bank one first.
Hopefully the bad heater is there and you won't have to undo bank 2.
My book shows the downstream connectors are gray (and mine are). The upstream connectors are supposed to be green but mine are a translucent yellow.
One of your heaters has probably melted and is drawing too much current when the PCM turns it on. Keep this in mind while troubleshooting: the O2 sensors have to be around 600° before
they start working. The heaters get them to that temp faster than engine heat alone. For sure the PCM enables the heaters when the engine is cold. I am assuming the PCM disables
the heaters once the engine is hot. If that is true you may have to let the engine cool between tests because the fuse won't blow if the PCM does not enable the heater circuit.
All four O2 connectors are shown. B1S2 is shown unplugged so you see the plug and the jack. They are hard to reach.
You need someone with small arms and strong fingers to undo them. The EGR pipe on the passenger side makes the
bank 2 connectors really hard to reach. Use a mirror and flashlight to see how the plugs unlock. Do the bank one first.
Hopefully the bad heater is there and you won't have to undo bank 2.
My book shows the downstream connectors are gray (and mine are). The upstream connectors are supposed to be green but mine are a translucent yellow.
One of your heaters has probably melted and is drawing too much current when the PCM turns it on. Keep this in mind while troubleshooting: the O2 sensors have to be around 600° before
they start working. The heaters get them to that temp faster than engine heat alone. For sure the PCM enables the heaters when the engine is cold. I am assuming the PCM disables
the heaters once the engine is hot. If that is true you may have to let the engine cool between tests because the fuse won't blow if the PCM does not enable the heater circuit.
The following users liked this post:
hlg1111 (May 17th, 2020)
#13
If those O2 sensor connectors are impossible to reach, there is another option.
The V6 intake manifold has front and rear crossover tubes.
If you remove the rear crossover you will have better access to all four connectors. You can't drive the car like this so you will have to measure the heater
resistance of all four sensors with your ohmmeter. The one with no resistance (zero ohms) between pins 3 and 4 is the one you need to replace.
The V6 intake manifold has front and rear crossover tubes.
If you remove the rear crossover you will have better access to all four connectors. You can't drive the car like this so you will have to measure the heater
resistance of all four sensors with your ohmmeter. The one with no resistance (zero ohms) between pins 3 and 4 is the one you need to replace.
Last edited by L84sky; June 8th, 2020 at 6:02 AM.
The following users liked this post:
hlg1111 (June 6th, 2020)
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