Reduced engine power - help

[Dak26]

I have a 2009 Aura XE with 175,000 - Recently the "Reduced Engine Power" warning came on the car would barley accelerate and run very rough. I turned the car off for about 10 minutes, started it back up and it ran fine for a while.
This problem continued to happen intermittently (mostly occurring while parked for 4 or 5 minutes) but has also happened while driving normally. Each time it happens I am usually able to correct the problem by pulling over and shutting the car off for 10 minutes. (a couple of times it took a little longer)

I took it to a local mechanic who ran diagnostics and told me the Knock sensor need to be replaced and they made that repair. This did not fix the issue so I too it back. Next, the mechanic said it was probably the throttle position sensor and they replaced that. - Still not solved -

I am looking for a new mechanic, but has anyone experienced this issue and found a solution.

Also, the service ESC, traction warnings have been popping up intermittently for a year -

Thanks in advance

[greenman]

i would need the code history since the issue began.

[Cowboy]

Hello all. I have 2008 Saturn Aura with 159,000 miles. The car drives well but intermittently the message "reduced engine power/traction control off" appears and the car starts to idle rough and the engine jerks so bad seems like the mounts are going to break. Upon starting the car there is a rattling noise coming from the engine but it stops after the engine warms up. I have not had it scanned for codes while it is reduced power mode but
p1682 comes up as well as the knock sensor code, a throttle actuator code, and a PCM code. Does anyone know how to fix the reduced engine problem? Any and all advise is welcome.

[fdryer]

1-Members not following up leave threads unresolved.

2-Rattling (159k miles) - maybe the catalytic converter falling apart and blocking exhaust flow?

3-Reduced power mode is about the drive by wire system; servo driven throttle, electronic pedal and ecm.

What's the maintenance history of this car? The knock sensor may be a cascade effect from other problems as knock sensors tend to last the life of most vehicles.

[Cowboy]

Thanks for the reply. The maintenance performed are as follow:

-throttle body cleaned(6/2016)

-exhaust camshaft solenoid replaced(7/2016)

-spark plugs replaced(8/2016)

-after noticing oil in two spark plug wells, replaced valve cover gasket and the o-rings(8/2016)

[fdryer]

I'm not familiar with Aura's and do not have access to service manuals or service bulletins. There does appear to be a recurring problem with this error code, P1682, with one place addressing it; http://forums.edmunds.com/discussion...er-problems/p6. GM customer service seems to be answering some queries but whether or not resolutions solve issues is anyone's guess. You might have to search around for other places that address this error code if a GM tech doesn't chime in with an answer.

I'm not aware of Aura's with variable valve timing. With different vvt designs, each auto maker uses what they consider their best ideas for fuel economy while increasing performance. VVT is the latest performance design but with it comes issues that may not have been seen during development before integration into EFI systems. I wonder if this is contributing to your reduced power mode issues. I have a drive by wire system in my L300 but without vvt.

Variable valve timing technology; http://www.aa1car.com/library/variable_valve_timing.htm

Reduced power mode is a default program to ensure a runaway engine doesn't occur. With millions of vehicles using dbw systems, there are little to no reported real issues of runaway engines with reduced power mode in place to prevent it. The components making up the error code for reduced power mode are; electric servo throttles, electronic accelerator pedals and ecm along with wiring. The few instances of reduced power occurring in Saturns are related mostly to the servo throttle actuator assembly and associated wiring. To my knowledge, only one Vue member reported a problem and was solved by replacing his throttle assembly. Upon opening the faulty throttle assembly, he remarked that there are parts that are recognizable but not easily serviceable.

[Cowboy]

Thanks for you help. I will test my throttle body and the wires.

[mmtphoto]

Just my experience but when I got my 97 XR it had all kinds of dash warning lights on and erratic driving problems. I eventually replaced the negative battery cable and installed an Advance Auto AGM battery to replace the suspect battery it had when I got it. I also added, from the battery, another ground cable from the neg post to the radiator support, and one from the driver side strut tower to the engine at the intake manifold.

At the very least thoroughly check your battery connections both at the battery and the other ends, this is a known issue.

[mmtphoto]

it is an 07 XR btw

[Cowboy]

Thanks for the advice. I will thoroughly inspect the cables. It's a 2008 XE 2.4L engine. I cleared the codes the other day and drove about 22 miles and the car went into reduced engine power/traction control off mode again. While in this mode I was able to limp to OReilly to scan the codes. The usual P1682 came up and a new code C0242(Power train Control Module/TCS malfunction) What would set code C0242?

[emidd27]

Have you fixed the issue? I am having the exact same issue.