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U1000 reduced engine power - 03 2500 Silverado 6.0 P0220

Model: 03 2500 Silverado 6.0 Fault Code: P0220 Posted: 2017-01-04 05:41

Code = U1000 Driver Info Center = Reduced Engine Power Check Engine Light = None A month ago, I started to get the Driver Info Center message stating "Reduced Engine Power". Of course, the truck would go down to crawl mode. No Check Engine Light. I have a bluetooth Lemur OBD2 scan dongle and I would reset the check engine light before the truck slowed from 50mph to 40... then the truck would wake back up and I would continue on. Typical internet/YouTube suggested repair was either the drive by wire TPS and/or the wiring harness. I replaced the harness - no change in issue. Then I changed the TPS unit. Problem went away for about a month. The past 2 days, the issue came back. I am not convinced that it is the wiring harness or the TPS, since the scan tool shows good response from the TPS. The Lemur scan tool is showing me a list of suggested fixes, based on other people's findings. However, since the U1000 is a pretty generic code and needs a secondary code to refine the issue (which I do not have a secondary code)... I am not sold on replacing a PCM, gauge cluster or whatever else. ---But the loose or dirty ground wire fix suggestion seems simple, and proper regardless of the outcome. Anyone else have a similar issue?

Related fault codes
P0220
Comments (16)
Anonymous 2017-01-04 09:27

you do NOT have the limur left in the ALDL? Do not operate with ANYTHING in ALDL. Any recent work, added electrical, new parts - GPS, AUDIO ? Did you add anything? No other codes?

Anonymous 2017-01-04 12:47

A new code just surfaced finally. P0220 Nothing new installed And you can run the Lemur blue driver in the vehicle while driving. How else can you monitor live data? plus the mfg says you can.

Anonymous 2017-01-04 13:07

What Mfg says you can- GM ? U1000 -The first check was removing anything from ALDL, as well as questions above. Is vehicle STOCK ? ANYWAY lets make it easy - clear codes then drive with it disconnected for a test - quick easy cheap. then rescan codes. The p0220 is the likely reduced power issue, I will post some tests later - busy day today. P0220 TPS B Circuit Malfunction

Anonymous 2017-01-04 13:47

Can you look at Freeze frame -p0220 - did it show TPS2 voltage ? Can scanner observe TPS 2 voltage live data... The PCM has seen a unexpected voltage on signsl from TPS2 either hi or low -less than 0.28 volt or greater than 4.60 volts. So unless current V is outside that consider intermittent.

Anonymous 2017-01-04 14:30

kev2 wrote: What Mfg says you can- GM ? U1000 -The first check was removing anything from ALDL, as well as questions above. Is vehicle STOCK ? Look.. I appreciate the help. But I don't need anyone to behave or assume like that. Always consider that you do not know the background of the person on the other end of the computer - or whom they work for or their past experience level.. Because of that, always treat people with respect. For what it's worth, when the truck faults, it only takes a few seconds to plug in the dongle and about 10 seconds to clear the code, all while coasting. In addition, obtaining live data can only be accomplished while operating. So - let's get over this - okay? Discover more engine Ram Pickup OBD Codes Once I get home, I will look deeper. But to answer your questions, an ALDl is the older late 80's diagnostic port. (pretty much the paperclip port while I was in the business) --You must mean if I have anything plugged into the OBD2 port when the issue occurs. The answer is no. The truck is stock.

Anonymous 2017-01-04 14:40

kev2 wrote: Can you look at Freeze frame -p0220 - did it show TPS2 voltage ? Can scanner observe TPS 2 voltage live data... The PCM has seen a unexpected voltage on signsl from TPS2 either hi or low -less than 0.28 volt or greater than 4.60 volts. So unless current V is outside that consider intermittent. I haven't had time to capture some live data. I may have time tonight. I searched for bulletins and found some instructions on voltage testing, but I will have to look up the service manual to find the terminal IDs. I brought home my laptop so I can access the manuals. At the last clearing of the code, this was the result. The Lemur emails me the report when it happens. Keep in mind that this afternoon was the first time I saw a companion code to the U1000. Finally, some direction to the generic communication fault. P0220 CODE DEFINITION: • Throttle Position (TP) Sensor 2 Circuit 5 POSSIBLE CAUSES: • PCM has failed • TP sensor 2 ground circuit is open • TP sensor 2 has failed • TP sensor 2 signal circuit is open or shorted to ground • TP Sensor 2 VREF (5v) circuit is open TOP REPORTED FIX: • Replaced Throttle Body 21 FREQUENTLY REPORTED FIXES: • Cleaned Throttle Body • Performed Powertrain Control Module (PCM) Programming • Repaired Engine Ground Strap w/P0120, P1516 • Repaired Engine Wiring Harness • Repaired Ground G103

Anonymous 2017-01-04 14:51

I am trying to help - AND I do this free as I do my own work... sometimes limited time makes awkward replies.... When I type in code looking for a trouble tree it gives me the TSB's and quick checks. And I add them first. Here we see skill levels range from professional to not a clue. Doing auto repairs for years sometimes old terms stay in memory, ALDL, ECM, worst yet I do mostly domestic, so am even more confusing to import owners.

Anonymous 2017-01-04 14:56

Did anything appear in freeze frame? Check th TB wiring, often the first several inches will be a fail point, clean corrosion free, They talk of water intrusion IDK, if you could observe V as you wiggle connector and harness, scroll down to DIA #4 http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=40859

Anonymous 2017-01-04 15:48

Freeze frame upon starting the truck and getting a fault. Live data shows throttle position from 14.9% idle to 99.9% full throttle. No anomalous data in between. Purely an intermittent issue. Make:Chevrolet Year:2003 Trouble Code P0220 triggered Freeze Frame. Code Def: Throttle/Pedal Position Sensor/Switch "B" Circuit PID : Description : Value 04 : Calculated Engine Load Value : 0.0 % 05 : Engine Coolant Temperature : 88 °F 06 : Short Term Fuel Trim Bank 1 : 0.0 % 07 : Long Term Fuel Trim Bank 1 : 0.0 % 08 : Short Term Fuel Trim Bank 2 : 0.0 % 09 : Long Term Fuel Trim Bank 2 : 3.9 % 0B : Intake Manifold Absolute Pressure : 28.9 inHg 0C : Engine RPM : 0 rpm 0D : Vehicle Speed : 0 MPH 10 : Mass Air Flow Rate : 0.00 lb/min 11 : Absolute Throttle Position : 15.3 %

Anonymous 2017-01-04 16:54

Well that is not much help But was worth a try... You say fault is current - check the TOS2 signal voltage.

Anonymous 2017-01-07 15:08

I have not had much time the past 2 days.. but there's a freeze from yesterday. One that happened while driving. I did notice that if I reset the fault with any pressure on the throttle, another identical error appears immediately. The terminals tested appropriately. I just bought an AC Delco throttle body assembly. Should have it on Monday. It may/may not solve it, but the $200 part is a cheap shot from the hip anyway. Make:Chevrolet Year:2003 Trouble Code P0220 triggered Freeze Frame. Code Def: Throttle/Pedal Position Sensor/Switch "B" Circuit PID : Description : Value 04 : Calculated Engine Load Value : 38.4 % 05 : Engine Coolant Temperature : 82 °F 06 : Short Term Fuel Trim Bank 1 : 7.0 % 07 : Long Term Fuel Trim Bank 1 : 5.5 % 08 : Short Term Fuel Trim Bank 2 : 11.7 % 09 : Long Term Fuel Trim Bank 2 : 7.8 % 0B : Intake Manifold Absolute Pressure : 24.2 inHg 0C : Engine RPM : 2639 rpm 0D : Vehicle Speed : 49 MPH 10 : Mass Air Flow Rate : 13.83 lb/min 11 : Absolute Throttle Position : 42.0 %

Anonymous 2017-01-07 17:00

I was hoping we would see the sensor voltages that were out of expected range. Is the wire open or shorted to power. Thinking positive - After the wiring and connector at TB the a TB is often the fix.... Let us know.

Anonymous 2017-01-10 06:17

Yesterday, the reduced engine message appeared several times and deteriorated to the point the the fault could no longer be cleared. Luckily, I was only a mile from home. At the same time, my AC Delco Throttle Body / TPS assembly arrived in the mail. 15 minutes later, the throttle body was replaced. Minimal learning of idle speed. 20 hours later involving 6 trips and no faults so far.

Anonymous 2017-01-10 12:26

being nosey would you mind sharing the cost of the TB? And so glad to hear its done... I was thinking an intermittent problem.

Anonymous 2017-01-10 12:35

https://amzn.to/2j50Qgp $170 free shipping

Anonymous 2017-01-10 15:11

that is a win scenario - diagnostics at +100$ an hour to troubleshoot and being a high failure component, good call.....