Service Engine Light

[nando_bu]

My wifes 2003 trailblazer has 7700 miles on it. The Service Engine Light just came on. The oil has been changed and tires rotated and balanced. The oil light is fine no problem with this. Does anyone know how to reset the Service Engine Light. Thanks

[GMMerlin]

This light indicates that there is a problem with the computor system on your vehicle.
Since you only have 7700 miles on your vehicle, take it back to the dealer and have them diagnos and repair the problem. This is considered a warranty repair and should be done no charge to you.

[TomGN]

I have 11,000 miles on my 2003 Trailblazer. Two weeks ago, it just stalled while accelerating. I rolled off the road and started it up - no problem. But the Service Engine Soon light came on. I arrived at work and read the manual. I shut off the car for awhile and restarted - no light. The next day, it came on while driving, and would not reset. I understand this light indicates an emissions issue. I checked the gas cap. The dealer found a code for an emissions problem, but could not cause it to re-occur. He suggested changing the fuel filter. He did and he said it showed "some" blockage (even he didn't sound convinced). I have read posts which suggest this light shows a computer problem, not an emissions issue.. can someone give me a categorical answer as to the type of problem this indicator relates to?

By the way, it's been fine since the filter was changed, so that might have been it.

[GMMerlin]

The SES light comes on when the PCM sees a problem with any one of the systems it monitors or controls..could be emmissions,transmission or some other PCM controlled mechanical device.

What code did the dealer find?
I have encountered a few intermittant stalling Envoys/Trailblazers over the last year, unfortunately I didn't find a common problem with them...loose connections, failed parts..nothing to indicate a model specific problem

[Bowlforthedog]

Nando I have 2003 TB as well. I have the LS model and I have had it in the shop twice for service engine light. Take it back and get it fixed.

[teksup95]

I was told by a service tech at a Chevy dealer once to make sure I hear the gas cap click 3 or 4 times when putting it back on, or I might get a CE light. Don't know if this helps, but I thought I'd throw it in.....

[03SSEi]

I also have an 03 TB. The SES light has come on since the mileage was at 5000 and set the code PO440, which is emmisions related. Something about the vacumm reading during the initial warmup. I have replaced the cap, to no avail. I have a reader and just keep clearing the code. I hate to leave it at the dealer, it is an inconvience. Anyone else had this problem?

[GMMerlin]

Originally Posted by 03SSEi

I also have an 03 TB. The SES light has come on since the mileage was at 5000 and set the code PO440, which is emmisions related. Something about the vacumm reading during the initial warmup. I have replaced the cap, to no avail. I have a reader and just keep clearing the code. I hate to leave it at the dealer, it is an inconvience. Anyone else had this problem?

P0440 is a large leak detected in the EVAP system.
If the code keeps coming back, you have a problem! Quite possibly a cracked filler neck.
Take the truck back to the dealer..your vehicle is covered under a 3 year 36000 mile bumper to bumper warranty...repairs will be done at no charge to you. You may even qualify for courtesy transportation while your vehicle is being serviced.

[tom.b]

Originally Posted by nando_bu

My wifes 2003 trailblazer has 7700 miles on it. The Service Engine Light just came on. The oil has been changed and tires rotated and balanced. The oil light is fine no problem with this. Does anyone know how to reset the Service Engine Light. Thanks

I have a 2003 tb I had that problem they changed out the gas tank it had a leak in it have not had that problem since then, hope that helps

[biggest424]

hi,i have a 2003 trailblazer,it has 19000 k miles and my service engine light keeps coming on .i bought a creader and the codes that showed up are 1221,1271 and 1680.could anyone tell me what htese mean.thanks

[03trailblazer]

Originally Posted by nando_bu

My wifes 2003 trailblazer has 7700 miles on it. The Service Engine Light just came on. The oil has been changed and tires rotated and balanced. The oil light is fine no problem with this. Does anyone know how to reset the Service Engine Light. Thanks

VERY SIMPLE
1. Turn key to the "on" position but don't start car
2. Pull the PCM BAT and PCM IGN fuses in engine compartment
3. Wait approximately 5 minutes
4. Turn ignition off
5. Replace fuses
6. Start the car and the make sure the light has went off

[dach95]

I once had SES light come on. I investigated a little and found that the day before, some butthead who filled up my car fail to close tight my gas cap. After tightening it and driving a few blocks, the SES light just went off. Hope you problem is as simple as this...

[BRD]

Originally Posted by dach95

I once had SES light come on. I investigated a little and found that the day before, some butthead who filled up my car fail to close tight my gas cap. After tightening it and driving a few blocks, the SES light just went off. Hope you problem is as simple as this...

It usually is. Replace the gas cap and allow the PCM time to do its job - a pressure test on the fuel system. It'll clear the SES. Disconnecting the battery or pulling the fuses will also turn off the SES light but you may be masking other issues. If the filler pipe has come loose from the gas tank, as many have on the extended wheelbase TB's & Envoys, you may be eligible for a fix by GM under Program 05012.