Need help ... 96 LT4 SES light question
Thread Starter
Burning Brakes
Joined: Feb 2002
Posts: 871
Likes: 1
From: Union KY
Need help ... 96 LT4 SES light question
Last week, my SES light came on and hard set codes 101 and 108. Prior to this glich, I'd reoiled my C&N air filter (the day before), so suspecting a oil fouled MAF cleaned it with brake fluid. After reassebly, the light came back on within five miles. Then I recleaned the MAF and reinstalled the GM dry filter. In ten miles, the SES light still came back on.
Of possible note, the initial episode occured about five miles after refuelling and was accompanied by a few seconds of very slight rough running. That one short moment aside, the engine has run flawlessly.
Any help would be appreciated. I hate to take it to the shop and pay someone to put a new MAF on it when that was the cure and I'd hate to buy one myself and find out it wasn't the problem. Cire96 :confused:
Of possible note, the initial episode occured about five miles after refuelling and was accompanied by a few seconds of very slight rough running. That one short moment aside, the engine has run flawlessly.
Any help would be appreciated. I hate to take it to the shop and pay someone to put a new MAF on it when that was the cure and I'd hate to buy one myself and find out it wasn't the problem. Cire96 :confused:
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: Need help ... 96 LT4 SES light question (cire96)
Ok, a little research shows the 101 as a MAF problem and the 108 as a MAP problem. They are related.
If the car is running ok now, then disconnect one side of the battery for a minute and reconnect. See if that eliminates your SES light.
This is a good first step and may work if your MAF is all cleaned up now.
If the codes return, post the running condition of the car and the codes you receive. I'd post the Helms troubleshooting pages but that'd be quite cumbersome as there are many.
[Modified by Dan Parker '96, 5:30 PM 10/16/2002]
If the car is running ok now, then disconnect one side of the battery for a minute and reconnect. See if that eliminates your SES light.
This is a good first step and may work if your MAF is all cleaned up now.
If the codes return, post the running condition of the car and the codes you receive. I'd post the Helms troubleshooting pages but that'd be quite cumbersome as there are many.
[Modified by Dan Parker '96, 5:30 PM 10/16/2002]
Thread Starter
Burning Brakes
Joined: Feb 2002
Posts: 871
Likes: 1
From: Union KY
Re: Need help ... 96 LT4 SES light question (Dan Parker '96)
Dan:
Thanks. To clarify, the codes were cleared each time by disconnecting the battery in between each instance of the SES light coming back on. Last night, I decided to recheck everything and found that the rubber MAF boot was not correctly mated to the filter inlet on the bottom edge - such that there was a gap about a half inch wide and two inches long.
I reassembled it correctly and again disconnected the battery for five minutes. So far, so good with the light staying off during the ten mile drive to work today. I'll report again if that ends the problem.
Do you see any reasonable possibility that such a opening after the air filter and before the MAF could be the culpret? I can't, but electronics are my real weakness. Cire96
Thanks. To clarify, the codes were cleared each time by disconnecting the battery in between each instance of the SES light coming back on. Last night, I decided to recheck everything and found that the rubber MAF boot was not correctly mated to the filter inlet on the bottom edge - such that there was a gap about a half inch wide and two inches long.
I reassembled it correctly and again disconnected the battery for five minutes. So far, so good with the light staying off during the ten mile drive to work today. I'll report again if that ends the problem.
Do you see any reasonable possibility that such a opening after the air filter and before the MAF could be the culpret? I can't, but electronics are my real weakness. Cire96
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: Need help ... 96 LT4 SES light question (cire96)
The misaligned intake boot shouldn't have caused a problem. The 101 may have been caused by getting a bit of oil on it (causing goofy frequency readings) or the connection to the MAF not being complete/secure (be sure to check the connector).
If it was oil then it may have burned itself off by now (and with the help of you cleaning it). And/or the MAF connector has started making a good connection.
For the 108 code (the MAP related one). The only far out guess I have (without resorting to electrical schematics) is that it may have shared the same 5.0volt reference circuit as the MAF and a poor MAF connection may have confused it. This is a huge guess as I'm rather disconnected from the whole situation :).
Hopefully this condition has remedied itself and you are good to go. Good luck.
If it was oil then it may have burned itself off by now (and with the help of you cleaning it). And/or the MAF connector has started making a good connection.
For the 108 code (the MAP related one). The only far out guess I have (without resorting to electrical schematics) is that it may have shared the same 5.0volt reference circuit as the MAF and a poor MAF connection may have confused it. This is a huge guess as I'm rather disconnected from the whole situation :).
Hopefully this condition has remedied itself and you are good to go. Good luck.
Thread Starter
Burning Brakes
Joined: Feb 2002
Posts: 871
Likes: 1
From: Union KY
Re: Need help ... 96 LT4 SES light question (Dan Parker '96)
Dan;
The SES light is back on. Yesterday, after a full warm up, I disconnected the battery and the light did not reignite thereafter during a ten minute drive. But after the engine cooled for four hours, it immediately relit aftter start up. Does that tell you anything? Cire96
The SES light is back on. Yesterday, after a full warm up, I disconnected the battery and the light did not reignite thereafter during a ten minute drive. But after the engine cooled for four hours, it immediately relit aftter start up. Does that tell you anything? Cire96
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Re: Need help ... 96 LT4 SES light question (cire96)
I looked at my 96 FSM, it says if 101 is set and 108 is set, look at 108 first. (It actually say "Any MAP DTC should be corrected first", first paragraph on right side of page page 6-322). 108 is "MAP sensor circuit high voltage", meaning the MAP sensor circuit is stuck high. There's a trouble shooting procedure, but the basic issue is if the connector/wiring harness to the PCM is stuck at 5V or even 12V? The MAP sensor circuit has three wires, 5V reference, sensor ground and the actual MAP sensor signal. If you have a multimeter you can test the MAP sensor and it's output voltage to see if it's stuck at 5V.
Eric
Eric
