P1516 , U0107, C0242-71 codes...
04-10-2018, 12:37 AM
#1
P1516 , U0107, C0242-71 codes...
I have a 2007 3.8 Lucerne 160k miles that is giving me trouble.
Any thoughts from the experts out there is appreciated.
The traction control light will come on and message display reads service traction control and reduced engine power. Sometimes the engine light comes on and sometimes it doesn’t.
This happens randomly both while driving or at start up. Overnight(so far) it clears up and reoccurs after 1~5 days of short drive to & from work. Clearing the codes with scan tool solves it until it reoccurs.
One time while in limp mode the throttle was at the max. limit (1500rpm ish) and when I would remove foot completely from accelerator pedal, the throttle would not close and remain at 1500ish rpm until I hit the brake and stopped. Then it would act like the throttle was not opening and no power trying to move again then after a few seconds jump open enough to actually pick up any speed.
When codes are cleared it magicly runs perfect until the codes reappear.
My thought is a bad throttle body just looking at the codes & symptoms.
But I wonder could this be a bad ground or some other issue causing a communication problem?
After clearing codes these ones are what I found when scanning again.
P1516
U0107
C0242 symptom 71
Message display reads:
Reduced engine power,
Service Traction Control
Traction control light in dash is iluminated
Any thoughts from the experts out there is appreciated.
The traction control light will come on and message display reads service traction control and reduced engine power. Sometimes the engine light comes on and sometimes it doesn’t.
This happens randomly both while driving or at start up. Overnight(so far) it clears up and reoccurs after 1~5 days of short drive to & from work. Clearing the codes with scan tool solves it until it reoccurs.
One time while in limp mode the throttle was at the max. limit (1500rpm ish) and when I would remove foot completely from accelerator pedal, the throttle would not close and remain at 1500ish rpm until I hit the brake and stopped. Then it would act like the throttle was not opening and no power trying to move again then after a few seconds jump open enough to actually pick up any speed.
When codes are cleared it magicly runs perfect until the codes reappear.
My thought is a bad throttle body just looking at the codes & symptoms.
But I wonder could this be a bad ground or some other issue causing a communication problem?
After clearing codes these ones are what I found when scanning again.
P1516
U0107
C0242 symptom 71
Message display reads:
Reduced engine power,
Service Traction Control
Traction control light in dash is iluminated
04-10-2018, 01:54 PM
#2
Senior Member
True Car Nut
P1516 Actual throttle position not in predicted range
U0107 Lost communication with throttle actuator control module
C0242 ECM indicates Traction Control malfunction
U0107 is most telling to me. C0242 is a byproduct, P1516 is "I expect the throttle position to be at xx% and I see it is at a different position than I expected and now I have become sad and need to tell someone about this feeling, I've known Throttle Actuator Control Module since I was born and I miss our close relationship". The different position could be 0% because of lost communication or some other % because the flaky electrical connection causes a major disparity between commands being received and completed and telemetry used for confirmation.
The actuator and control module are pricey. I'd check electrical first.
In what part of the world does this car live?
Have any good rain (therefore puddles etc.) lately?
Last edited by CathedralCub; 04-10-2018 at 01:55 PM. Reason: Corrected a typo
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lespaulr0cker (04-10-2018)
04-10-2018, 06:53 PM
#3
CathedralCub thanks for steppineg in to offer thoughts on this.
I’m in the Cincinnati, OH area and yes we have been getting rain & wet weather. We also get occasional snow and they put that stuff on the roads here that makes everything coorode. I haven’t driven through any deep water.
I was thinking the same that the TCS error may be triggered by the throttle issue. The scan tool description for C0242 Symptom 71 reads: “Invalid serial data received”. Not sure if this indicates a communication problem or just an incorrect data value due to the communication issue with the Thottle Actuator Control Module. I’m thinking the latter because it’* not a loss of communication error but it’* only guesswork on my part.
I’m thinking I will try jiggling associated wiring & checking connectors to see if I can get the error to occur. Problem is I’m not sure where this stuff would be found. I can find the throttle body easy enough and jiggle/check that wiring & connector. Not sure where the Throttle Actuator Control Module is? And any grounds or other associated wiring & connectors?
Is anyone out there familiar with this on a Buick Lucerne?
I’m in the Cincinnati, OH area and yes we have been getting rain & wet weather. We also get occasional snow and they put that stuff on the roads here that makes everything coorode. I haven’t driven through any deep water.
I’m thinking I will try jiggling associated wiring & checking connectors to see if I can get the error to occur. Problem is I’m not sure where this stuff would be found. I can find the throttle body easy enough and jiggle/check that wiring & connector. Not sure where the Throttle Actuator Control Module is? And any grounds or other associated wiring & connectors?
Is anyone out there familiar with this on a Buick Lucerne?
04-10-2018, 08:33 PM
#4
UPDATE: I took a look under the hood and located throttle body. The wires from that go into a harness with many wires that seems to terminate at a large connector on the right front wheel well.
With the engine running I did some hard jiggling of the wires from the throttle body back to the large connector. The problem didn’t re-occur while doing this.
I shut it down and removed the throttle body connector and the large harness connector. They both look really clean inside and the mating pins look new & shiny.
I do notice now that I’m paying more attention to it that it is hesitating slightly on start up. So I decided to “exercise” the throttle body by punching the accelerator while I park. As soon as it hit. About 4000rpm the dinger sounded and the reduced engine power/traction control error occurred. I don’t have a scan tool here but I’m guessing it’* the same code situation. The throttle response does not seem consistent when in limp mode. When I shut it down in limp mode I notice a high pitched sound coming from 5e throttle body for about five seconds, then it makes a click sound like it closed and no sound after that.
This and the hesitating at start up(with no error) is leading me to believe the throttle body may be bad or need cleaning.
With the engine running I did some hard jiggling of the wires from the throttle body back to the large connector. The problem didn’t re-occur while doing this.
I shut it down and removed the throttle body connector and the large harness connector. They both look really clean inside and the mating pins look new & shiny.
I do notice now that I’m paying more attention to it that it is hesitating slightly on start up. So I decided to “exercise” the throttle body by punching the accelerator while I park. As soon as it hit. About 4000rpm the dinger sounded and the reduced engine power/traction control error occurred. I don’t have a scan tool here but I’m guessing it’* the same code situation. The throttle response does not seem consistent when in limp mode. When I shut it down in limp mode I notice a high pitched sound coming from 5e throttle body for about five seconds, then it makes a click sound like it closed and no sound after that.
This and the hesitating at start up(with no error) is leading me to believe the throttle body may be bad or need cleaning.
04-10-2018, 10:17 PM
#5
Senior Member
True Car Nut
More often than not, I have found an electrical problem rather than a throttle body problem........usually it'* at the crimp of the connector in the harness to the wire.......sometimes there can be a break inside the insulation of the wire, due to flexing....
There could also be a serial data problem with the wiring......however diagnosis involves schematics, Tech II scanner, and trouble trees.....
Did find this TSB:
Subject: LD8, LH2, L37 Service Engine Soon (SES)/MIL Light Illuminated, “Engine Power Reduced” Message Displayed on Driver Information Center (DIC) with Multiple ECM DTCs P1516, P2101, P2119 or P2176 (Inspect Throttle Body Blade)
Models: 2006-2008 Buick Lucerne
2006-2008 Cadillac DTS
2007-2008 Cadillac SRX, STS, XLR
with 4.6L Northstar® V8 Engine (VINs A, Y, 9 — RPOs LD8, LH2, L37)
Condition
Some customers may comment that the MIL/SES light is illuminated and the message “Engine Power Reduced “ may be displayed on the driver information center. Technicians may find one or more of the following DTCs stored.
P1516–Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
P2101– Throttle Actuator Position Performance
P2119– Throttle Closed Position Performance
P2176– Minimum Throttle Position Not Learned
Cause
This condition may be caused by the throttle blade intermittently sticking in the closed position on some throttle bodies built prior to 2/21/2007.
Correction
Perform normal SI diagnosis for any DTCs that are set. If normal diagnosis doesn't reveal any concerns with the throttle body, inspect the throttle body blade operation using the steps below.
The engine should be at normal operating temperatures with the ignition key in the OFF position.
Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement in SI.
Gently push the bottom half of the throttle body blade inward to the closed position and release. The throttle blade should return to the rest position which is slightly open.
If the throttle blade returns to the rest position by itself, no further action is required. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement in SI.
If the throttle blade does not return to the rest position, replace the throttle body assembly. Refer to Throttle Body Assembly Replacement in SI.
Inspect Julian Date Code on New Part
Important: Throttle body assemblies with a Julian date code of 0527 or earlier should not be used for service.
There could also be a serial data problem with the wiring......however diagnosis involves schematics, Tech II scanner, and trouble trees.....
Did find this TSB:
Subject: LD8, LH2, L37 Service Engine Soon (SES)/MIL Light Illuminated, “Engine Power Reduced” Message Displayed on Driver Information Center (DIC) with Multiple ECM DTCs P1516, P2101, P2119 or P2176 (Inspect Throttle Body Blade)
Models: 2006-2008 Buick Lucerne
2006-2008 Cadillac DTS
2007-2008 Cadillac SRX, STS, XLR
with 4.6L Northstar® V8 Engine (VINs A, Y, 9 — RPOs LD8, LH2, L37)
Condition
Some customers may comment that the MIL/SES light is illuminated and the message “Engine Power Reduced “ may be displayed on the driver information center. Technicians may find one or more of the following DTCs stored.
P1516–Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
P2101– Throttle Actuator Position Performance
P2119– Throttle Closed Position Performance
P2176– Minimum Throttle Position Not Learned
Cause
This condition may be caused by the throttle blade intermittently sticking in the closed position on some throttle bodies built prior to 2/21/2007.
Correction
Perform normal SI diagnosis for any DTCs that are set. If normal diagnosis doesn't reveal any concerns with the throttle body, inspect the throttle body blade operation using the steps below.
The engine should be at normal operating temperatures with the ignition key in the OFF position.
Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement in SI.
Gently push the bottom half of the throttle body blade inward to the closed position and release. The throttle blade should return to the rest position which is slightly open.
If the throttle blade returns to the rest position by itself, no further action is required. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement in SI.
If the throttle blade does not return to the rest position, replace the throttle body assembly. Refer to Throttle Body Assembly Replacement in SI.
Inspect Julian Date Code on New Part
Important: Throttle body assemblies with a Julian date code of 0527 or earlier should not be used for service.
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04-10-2018, 11:56 PM
#6
Thanks for the input Tech II.
I put some stress on the harness but couldn't make it happen. Didn't go so far as to pull each wire, just pulled and vibrated the entire group from the TB to the big connector. Could be a bad wire/terminal somewhere else I guess.
On mine you actually have to push the top half of the blade to close it which I did and it did return to the rest position by itself. After setting for awhile the error reset and after reving it up to around 4000 rpm a few times it did reoccur again. I watched the blade while reving it and it appeared to move smoothly for what that'* worth.
I couldn't find any three digit Julian date on the throttle body, however I did see 6X24 dot peened onto the top near the other molded markings. I believe the car is an early 2007 build.
Not looking forward to having someone else dig into it for $waytomuch /HR :/
More often than not, I have found an electrical problem rather than a throttle body problem........usually it'* at the crimp of the connector in the harness to the wire.......sometimes there can be a break inside the insulation of the wire, due to flexing....
There could also be a serial data problem with the wiring......however diagnosis involves schematics, Tech II scanner, and trouble trees......
There could also be a serial data problem with the wiring......however diagnosis involves schematics, Tech II scanner, and trouble trees......
I couldn't find any three digit Julian date on the throttle body, however I did see 6X24 dot peened onto the top near the other molded markings. I believe the car is an early 2007 build.
Not looking forward to having someone else dig into it for $waytomuch /HR :/
04-11-2018, 05:00 PM
#7
UPDATE: I started it today and the errors were reset after sitting overnight. I noticed the check engine light soon after start up. I didn’t notice it on at start up but it may have been.
I took it back to the shop and they scanned & reset the codes. The codes they found were:
P0102 - 0 MAF sensor low voltage.
U0107 - 0 Lost communication with throttle actuator.
I did notice a little raw spot on a wire in the bundle that is routed over the metal part of the intake next to the throttle body. The plastic cable wrap is dried out and disintegrating causing exposed wires around the engine. I insulated this raw spot, not sure if it will help.
Made a couple stops and went home with no codes or errors yet. Reving the engine does not make it reoccur as of yet.
I took it back to the shop and they scanned & reset the codes. The codes they found were:
P0102 - 0 MAF sensor low voltage.
U0107 - 0 Lost communication with throttle actuator.
I did notice a little raw spot on a wire in the bundle that is routed over the metal part of the intake next to the throttle body. The plastic cable wrap is dried out and disintegrating causing exposed wires around the engine. I insulated this raw spot, not sure if it will help.
Made a couple stops and went home with no codes or errors yet. Reving the engine does not make it reoccur as of yet.
04-11-2018, 10:57 PM
#8
Senior Member
True Car Nut
Like I said before the only way to diagnose this is with a Tech II......you put the scan tool in "snap shot" mode and then you try to recreate th problem, and then you replay the data at the time the code occurs.......it'* just an invaluable tool......unfortunately it'* also a very expensive one......
But I am leaning towards a wiring/harness problem, especially with the "U" code.....the fact you could sometimes create the problem by revving the engine, this causes the engine to move and flex harnesses, setting the code....
But I am leaning towards a wiring/harness problem, especially with the "U" code.....the fact you could sometimes create the problem by revving the engine, this causes the engine to move and flex harnesses, setting the code....
04-12-2018, 01:00 AM
#9
Yep, I’m with yah. The crumbling protective tubing on the engine harness is terrible. They should make that stuff from materials that last 40 years.
I heard of a local shop who’* known for electical work. I’l take it over there and have them diagnose it like you said.
I heard of a local shop who’* known for electical work. I’l take it over there and have them diagnose it like you said.
04-26-2018, 10:29 PM
#10
UPDATE;
Well, I took it to the place I mentioned in the previous post and they said they checked all connections & such. Didn’t see anything wrong. The limp mode had reset when I started it and drove there. I dropped it off with no issue other then check engine light which was on when I stated it. Shop couldn’t make the problem happen. Said the codes were communication related. The guy said he did some research and heard of folks switching out PCM but didn’t sound 100% it would solve the problem. Trying to figure out what to do now, not wanting to experiment buying expensive parts to try :/
Well, I took it to the place I mentioned in the previous post and they said they checked all connections & such. Didn’t see anything wrong. The limp mode had reset when I started it and drove there. I dropped it off with no issue other then check engine light which was on when I stated it. Shop couldn’t make the problem happen. Said the codes were communication related. The guy said he did some research and heard of folks switching out PCM but didn’t sound 100% it would solve the problem. Trying to figure out what to do now, not wanting to experiment buying expensive parts to try :/