Error codes and gear issues 2009 Y Denali

[FBDenali]

I went to three different mechanics and all three gave me a different solution. So not really trusting any till i do some research.

My 2009 Yukon Denali has been a pain with "Service Stabilitrak" "Traction Control off" and "Service Stabilitrak" messages coming on. And at random times every few days it will shift very hard from 1st to 2nd gear, and in slow stop and go traffic when i press on the break it feels like it wants to keep going.

I went once to the dealer and did another check at a shop using a tech2 and this is what came up:

C0161 ABS break switch circuit
C0561 System disabled (invalid serial Data)
P0751 shift solenoid (ss) valve performance stuck off
P2273 HO25 Signal stuck rich bank2 sensor2
P0300 Engine misfire detected

Misfire history cyl.4 1574
Cycles of misfire data 72









Thanks in advance





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[FBDenali]

I went to three different mechanics and all three gave me a different solution. So not really trusting any till i do some research.

My 2009 Yukon Denali has been a pain with "Service Stabilitrak" "Traction Control off" and "Service Stabilitrak" messages coming on. And at random times every few days it will shift very hard from 1st to 2nd gear, and in slow stop and go traffic when i press on the break it feels like it wants to keep going.

I went once to the dealer and did another check at a shop using a tech2 and this is what came up:

C0161 ABS break switch circuit
C0561 System disabled (invalid serial Data)
P0751 shift solenoid (ss) valve performance stuck off
P2273 HO25 Signal stuck rich bank2 sensor2
P0300 Engine misfire detected

Misfire history cyl.4 1574
Cycles of misfire data 72

View attachment 194654View attachment 194655View attachment 194656View attachment 194657View attachment 194658







Thanks in advance





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Sorry for the long post I just wanted to get all the information I have posted


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[jhax01]

This may be way off track since I haven't heard your vehicle running so you'll have to judge that for yourself, but I recently did the AFM delete because of a lifter failure. When it happened the Service Stabilitrak and Traction Control lights/messages came on due to the misfiring it caused. I find it interesting to note that in your last photo, *all* of those cylinders misfiring are AFM cylinders. I'd check the plugs and possibly pop the valve covers to see if the rockers are loose -- that's a sure sign that the lifters have or are beginning to collapse.

 

[swathdiver]

Howdy BYB! Glad to see a fellow member with a Tech2!

C0161 - Your truck thinks the brakes are applied while you're driving.

DTC Descriptor

DTC C0161 00
ABS/TCS Brake Switch Circuit
DTC C0161 5A
ABS/TCS Brake Switch Plausibility Failure

Circuit/System Description

The EBCM receives a serial data message from BCM that the brake pedal is applied and to ensure that the states of their feedback circuits agree.

Conditions for Running the DTC

 The ignition is ON.
 The vehicle speed is greater than 16 km/h (10 mph).
 The ignition voltage is greater than 9.5 volts.

Conditions for Setting the DTC

 The brake pedal is sensed as applied for 6 minutes.
 The vehicle speed is greater than 21 km/h (13 mph).

Action Taken When the DTC Sets

The ABS/TCS/VSES if equipped, remains functional.

Conditions for Clearing the DTC

 The condition for the DTC is no longer present.
 The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The DTC C0161 00 can be set if the brake switch is applied while accelerating.

 

[swathdiver]

Now I ignored your next two codes because they have not returned. The 4th one, P2273 is more complex and could have impacted/caused the previous codes. For this I suggest you get a subscription over at AllDataDIY and look up the trouble codes and diagnostics for it.

As to the misfires, what engine is in your truck? The L92 or L9H or L94?

 

[FBDenali]

This may be way off track since I haven't heard your vehicle running so you'll have to judge that for yourself, but I recently did the AFM delete because of a lifter failure. When it happened the Service Stabilitrak and Traction Control lights/messages came on due to the misfiring it caused. I find it interesting to note that in your last photo, *all* of those cylinders misfiring are AFM cylinders. I'd check the plugs and possibly pop the valve covers to see if the rockers are loose -- that's a sure sign that the lifters have or are beginning to collapse.

That’s going to be my first plan of attack, now thinking about it i had a mechanic change the plugs he said he also cleaned the injectors. I’m thinking he might either
missed something or broke something in the process.


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[FBDenali]

Howdy BYB! Glad to see a fellow member with a Tech2!

C0161 - Your truck thinks the brakes are applied while you're driving.

DTC Descriptor

DTC C0161 00
ABS/TCS Brake Switch Circuit
DTC C0161 5A
ABS/TCS Brake Switch Plausibility Failure

Circuit/System Description

The EBCM receives a serial data message from BCM that the brake pedal is applied and to ensure that the states of their feedback circuits agree.

Conditions for Running the DTC

 The ignition is ON.
 The vehicle speed is greater than 16 km/h (10 mph).
 The ignition voltage is greater than 9.5 volts.

Conditions for Setting the DTC

 The brake pedal is sensed as applied for 6 minutes.
 The vehicle speed is greater than 21 km/h (13 mph).

Action Taken When the DTC Sets

The ABS/TCS/VSES if equipped, remains functional.

Conditions for Clearing the DTC

 The condition for the DTC is no longer present.
 The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The DTC C0161 00 can be set if the brake switch is applied while accelerating.

Hi swathdiver, the tech2 is from a mechanic i went to, i asked him to check and had no intention of fixing anything found through error codes. I just wanted to know what the error codes were to do my research here then go back well informed


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[FBDenali]

Now I ignored your next two codes because they have not returned. The 4th one, P2273 is more complex and could have impacted/caused the previous codes. For this I suggest you get a subscription over at AllDataDIY and look up the trouble codes and diagnostics for it.

As to the misfires, what engine is in your truck? The L92 or L9H or L94?

I looked it up, while saying to my self i should know this but I’m guessing since it’s a 2009 it’s L9H

Im also going to follow your suggestions I’ll update when i find something

Thanks


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[jhax01]

I looked it up, while saying to my self i should know this but I’m guessing since it’s a 2009 it’s L9H

Im also going to follow your suggestions I’ll update when i find something

Thanks


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Hmm...Interesting, I thought the L9H was only in the pick-up trucks. Kinda negates what I said then if that's what you have. It's still worth checking the plug condition on the misfiring cylinders tho.

 

[swathdiver]

Hmm...Interesting, I thought the L9H was only in the pick-up trucks. Kinda negates what I said then if that's what you have. It's still worth checking the plug condition on the misfiring cylinders tho.

There was a small run of very late 2008s and some more 2009 Tahoes that got the L9H too. Would someday be collectible I reckon.

He really needs to check his RPO sheet in the glovebox though to be sure.