I have a '06 STS4 V8.

Here is a list of items for discussion.

Battery replacement: The battery died and I replaced it with OEM from the dealer.

After the battery replacement, symptoms.

Blown speaker sound: at time the speakers sound blown. This symptom comes and goes (it is not music, genre or song specific).

Throttle failure: at times when driving the car, it fails to respond and it must be shutdown and restarted. When this symptom occurs the car appears to be in an idle mode and the traction control light comes on. At restart the car works as it should.

Troubleshooting, up until now.

I have constantly watched the voltage. A typical startup voltage is ~14vdc and once the car is warmed up it maintains ~13.3vdc. Voltage range is ~12.9 to ~14.4.

The problem does not appear to be voltage induced.

Please only reply if you are familiar with this issue.

D.

 

Do you have access to Tech 2 and service info?

 

Thanks for the questions Slowroll. Actually, I don't have access to that information.

Here is my latest troubleshooting:

Code scanner:

P0102 -- MAF or VAF A circuit low input

P1101 -- Manufacturer Control Fuel Air Metering

P0068 -- MAF/MAP Sensor Throttle Position Correlation

P0106 -- MAP/BARO CKT Range/Perf

P2108 -- TAC Module Performance

P0174 -- System Too Lean (Bank 2)

P0102 -- MAF or VAF A circuit low input (Second Occurance)

P1101 -- Manufacturer Control Fuel Air Metering (Second Occurance)

So, Here's the deal... I want to fix this w/o the dealer (last resort). I have other cars so this car can be parked for now.

Before the battery ordeal the "P0068 -- MAF/MAP Sensor Throttle Position Correlation" code was already thrown. This, however, did not affect the way the car ran or drove. The other codes are new.

Until next time, thanks for the replies.

D.

 

06 under 50k should be under warranty, Ca or NYC and some other areas longer. Codes seem to center around MAF. If car has oiled air filter(K&N) and it is/was over oiled will kill MAF, make sure throttle plate is clean. Car may need new MAF sensor.

 

Thanks slowroll. The car is well over 50K; actually just over 80K. You were right about the MAF.

I cleared the codes yesterday and attempted to start the car w/o the MAF. Normally when the MAF is upplugged a car will not idle.

My STS did idle. In fact the first error thrown was the low input volage on the MAF and the car ran normal. I cleared the codes again.

I plugged the MAF back in and started the car. The exact same indications as w/o the MAF.

I do not have a K&N. Maybe the MAF was faulty before the battery as the prior codes indicated. Whatever the cause the EMS did a sufficient and safe job at operating the engine w/o the sensor. I am impressed, although the lack of symptoms was misleading at first. (CEL can come on if the gas cap is leaking as we all know).

I ordered a new sensor from GMPartsDirect.com.

(Rant)
That's an intersting story also. Appearantly Flow automotive can give you about 1/2 off on the list price for parts. The GM dealer in town (Riverside, CA) had a markup on the MSRP. The list cost was ~125$ and Flow is only 69$. The Riverside Dealer marked up the MSRP ~9%. It is a shame about the markup because I do like a personal experience rather than internet facelessness.

Now, I will have to figure out the peridic speaker noise problem. I do hope that my amplifier is not faulty.

Thank you for the replies.

D.

 

FYI:

I did a search on code: “P1101 -- Manufacturer Control Fuel Air Metering” and I do believe this explains the process in which allows the Cadillac to run seemingly unaltered when a critical sensor (such as the MAF) is faulty.

Title:
Fuel metering control system and cylinder air flow estimation method in internal combustion engine
Do***ent Type and Number:
United States Patent 5448978


Abstract:
Fuel metering control system in an internal combustion engine utilizing adaptive control having an intake manifold wall's fuel adherence plant. In the system, an actual air/fuel ratio in the individual cylinders is accurately estimated using an exhaust manifold model with an observer. Also, an actual cylinder air flow is estimated using a fluid model. Based on them, a desired cylinder fuel flow is determined by dividing the actual cylinder air flow by a desired air/fuel ratio and an actual cylinder fuel flow is determined by dividing the actual cylinder air flow by the estimated actual air/fuel ratio. The adaptive controller operates such that the actual cylinder fuel flow constantly coincides with the desired cylinder fuel flow. In an embodiment, in order to respond the change in wall adherence parameters, a compensator is connected in series with the wall adherence plant, a virtual plant incorporating the compensator is postulated and when the transfer characteristics of the virtual plant is other than 1 or thereabout, the adaptive controller is operated to have a transfer characteristics inverse thereto. At the same time, a method for estimating cylinder air flow inducted in the engine using the aforesaid fluid model is explained.

Reference:

Fuel metering control system and cylinder air flow estimation method in internal combustion engine. (N/A). Retrieved February 15, 2009 from http://www.freepatentsonline.com/5448978.html

 

I changed out the MAF sensor and the problem still exists. The same trouble codes exist. I am considering the ECM but do not know if the dealer has to program it for the specific application.

I have read that some XLRs had a problem in 04 with the programming of the ecm and there is a TSB out for it.

Is anyone familiar with this problem?

D.

 

A trip to dealer is required to program ECM.

 

If I purchase a new ECM do I need to have the dealer program it?

Thanks,
D.

 

A trip to the dealer fixed the problem. A rodent literally ate a lot of the wiring in my engine compartment!!! If I find that rat I'm going to kill it!


D.