Check engine light, 99 Silhouette

Tiny
ALLENMOB
  • MEMBER
  • 1999 OLDSMOBILE
We purchased a used 1999 oldsmobile silhouette a few weeks ago, 132000 miles. (3.4 engine). 3 times I have received the check engine light on the instrument panel. Each of the times occurred after refueling a nearly empty tank (1/4 tank or less). The last time I tightened up the gas cap and the problem was solved but it has stayed on for the day this time. Also, right about the times that the light comes on the engine "hiccups', sometimes severely, and continues to do so until the light finally goes out. Any suggestions on what I need to check and/or how to fix and prevent this issue? Thanks!
Thursday, October 25th, 2007 AT 9:42 AM

6 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Get the vehicle to autozone and get it scanned for codes and comeback with it-this it the starting point for diagnosis.

Gas cap! Sounds like there's a problem with the evaporative system could be a purging solenoid/charcoal canister

OBD II also monitors the evaporative emissions (EVAP) system, but only once during a drive cycle. The purpose here is to detect leaks that allow fuel vapors to escape into the atmosphere. OBD II does this by applying vacuum or pressure to the fuel tank, vapor lines and charcoal canister. If OBD II detects no air flow when the EVAP canister purge valve is opened, or it detects a leakage rate that is greater than that which would pass through a hole 0.040 inches in diameter (0.020 inches for 2000 and up model year vehicles, which is the size of a pin prick), the EVAP system is malfunctioning and OBD II sets a code.

If you have a P0440 code indicating a fault in the EVAP system, finding the leak can be a challenge. The first place to start is the gas cap. A loose-fitting or damaged cap can allow enough air leakage to set a code. To find a vapor leak, you may need a leak detector that uses smoke and/or dye.
Was this
answer
helpful?
Yes
No
Tuesday, October 30th, 2007 AT 12:27 AM
Tiny
ALLENMOB
  • MEMBER
  • 4 POSTS
Auto zone gave me an error code 742, about the transmission. 2 transmission places both gave me the same error code (+ a few more like a code for trying to start the car with an "uncoded" key). I'm going to take it to another mechanic and see what he says. They all say it's the transmission and the light/engine trouble coming on after a tank fill-up is nothing but a strange coincidence. Thanks.
Was this
answer
helpful?
Yes
No
Thursday, November 1st, 2007 AT 4:36 AM
Tiny
ALLENMOB
  • MEMBER
  • 4 POSTS
P0742 TCC circuit stuck on

P1629 Fuel enable/incorrect no signal

P1811 Max adapt & long shift/ has to due with slippage of transmission.

The 3rd mechanic said that I have a celenoid? That needs replaced and the van should be fine. That sound right?
Was this
answer
helpful?
Yes
No
Thursday, November 1st, 2007 AT 4:33 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The transmission is it shifting properly or delay in shifts?

The transmission operation has nothing to do with the evaporative system. That was your original problem- The last time I tightened up the gas cap and the problem was solved but it has stayed on for the day this time. I am assuming when it corrrected the problem it has to do with the Evap System not the tranny.

TCC " transmission converter clutch " solenoid could be the problem here or other shifting solenoids involved.
Was this
answer
helpful?
Yes
No
Thursday, November 1st, 2007 AT 4:48 PM
Tiny
ALLENMOB
  • MEMBER
  • 4 POSTS
I've had the tcc and shift 1/2 (?) Solenoids replaced and the van shifts fine until it gets warmed up then it starts shifting hard. The mechanic said he didn't clear out the error codes from the computer and that is what is causing the problem to continue. The engine light hasn't come on since the parts were replaced. Is there anything else I should check? . Before or after the codes are cleared? . Will the computer clear out the codes itself or do I have to take it to have that done? Thanks!
Was this
answer
helpful?
Yes
No
Monday, November 12th, 2007 AT 3:11 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
If you know all else is good on it-take it to autozone and have them clear it for free.

Good Luck my friend and thanks again for the donation feel free to comeback and tell friends about us.
Was this
answer
helpful?
Yes
No
Monday, November 12th, 2007 AT 4:19 PM

Please login or register to post a reply.

Related Check Engine Light Content

Is it Safe to Drive Check Engine Light?
VIDEO
Is it Safe to Drive Check Engine Light?
Instructional repair video
Check Engine Light
GUIDE
Check Engine Light
Why is my check engine or service engine soon turned on? In this guide we talk about what this is associated with this notorious light, what it is used for and what you...
VIEW MORE