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Codes P1514 and P1345, Check engine and Reduced power lights on?

Tiny
MJ_ORIGINAL
  • MEMBER
  • 2002 CHEVROLET TRAILBLAZER
  • 4.2L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 310,000 MILES
First post/New member. Fixed vacuum leak on fuel pressure regulator line to intake manifold. Helped with starting immediately or 2-3 crank. New or recent OEM spec parts only: plugs and coil, MAP, crankshaft and camshaft sensors. Radiator (water pump ordered pending). Cleaned throttle body off engine, not very dirty from last cleaning +- 2 years ago. Codes: P1514, P1345.
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Sunday, August 20th, 2023 AT 9:46 AM

17 Replies

Tiny
KEN L
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P1514 and P1345, correspond to specific issues with the throttle body control system and camshaft/crankshaft position sensor synchronization

P1514 - Throttle Actuator Control Module Throttle Actuator Position Performance:

So, I would replace the throttle body.

P1345 - Crankshaft/Camshaft Position Sensor (CMP/CKP) Correlation:

When you replaced the crankshaft and camshaft sensor did you do the relearn procedure?

1. Install a scan tool.
2. With a scan tool, monitor the powertrain control module for DTCs. If other DTCs are set, except DTC P1336, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC that set.
3. With a scan tool, select the crankshaft position variation learn procedure.
4. Observe the fuel cut-off for the engine that you are performing the learn procedure on.
5. The scan tool instructs you to perform the following:
- Block the drive wheels.
- Apply the vehicles parking brake.
- Cycle the ignition from OFF to ON.
- Apply and hold the brake pedal.
- Start and idle the engine.
- Turn OFF the A/C.
- Place the vehicle's transmission in Park (A/T) or Neutral (M/T).
- The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:
- Crankshaft position (CKP) sensors activity-If there is a CKP sensor condition, refer to the applicable DTC that set.
- Camshaft position (CMP) sensor activity-If there is a CMP sensor condition, refer to the applicable DTC that set.
- Engine coolant temperature (ECT)-If the engine coolant temperature is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.
6. With the scan tool, enable the crankshaft position system variation learn procedure.

IMPORTANT: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete.

7. Slowly increase the engine speed to the RPM that you observed.
8. Immediately release the throttle when fuel cut-off is reached.
9. The scan tool displays Learn Status: Learned this ignition. If the scan tool does NOT display this message and no additional DTCs set, refer to Symptoms - Engine. If a DTC set, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC that set.
10. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.

Please go over these guides and get back to us.
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Sunday, August 20th, 2023 AT 4:55 PM
Tiny
MJ_ORIGINAL
  • MEMBER
  • 8 POSTS
Throttle body arriving later today.
I have a Veepek/OBD Fusion app, so it's not bi-directional.
I have 'driving' relearn instructions, but can't attempt until Reduced Power is addressed. Will update. I'll copy instructions on relearn for your evaluation.
This has been very helpful, thanks.
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Tuesday, August 22nd, 2023 AT 1:44 PM
Tiny
MJ_ORIGINAL
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'driving' relearn instructions.
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Tuesday, August 22nd, 2023 AT 1:52 PM
Tiny
KEN L
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Yep, these look correct. Let me know what happens.
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Thursday, August 24th, 2023 AT 10:20 AM
Tiny
MJ_ORIGINAL
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  • 8 POSTS
Well, it turns out to be harder than I'd imagine doing the 'rolling relearn' on the highway outside of town after 10pm. Denied two nights in a row!
Option 1: Get advice on the best bidirectional scan/smart device around $150 +-, if it exists yet.
Or
Option 2: jack stand the rear end and.
Top speed is 55mph, so provided it's done gingerly, what could go wrong with plenty of open forward space?
Certainly not asking for permission, but seems reasonable with safety being #1.
Or is that too backwards, driving blind?
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Friday, August 25th, 2023 AT 6:14 PM
Tiny
KEN L
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Sometimes the logic takes longer than a couple drives, I would keep going to see what happens.
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Saturday, August 26th, 2023 AT 11:49 AM
Tiny
MJ_ORIGINAL
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Great Improvement!
I used the DFW tollway around midnight. Gotta pay, but there's 4 lanes + shoulder (not to mention the service road) for the 45mph deceleration series. Did the entire test 4 times.
Reduced Power light is OFF!
Service Engine light is still on, but the idle is without miss or knocks. Exhaust sounds normal. In Park I could raise rpm over +-3000 and would return to idle without struggling to not stall. Idle remains rough.
Codes: P1345 & a P0105; which referred me to an online description that MAF is at issue. 02’s TB don't have MAF sensor; it's just a tiny nub wired to the pre-plenum tube.
? What's next To Do?

Feeling much better,
The O MJ
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Monday, August 28th, 2023 AT 9:12 AM
Tiny
KEN L
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Nice work, okay for the next part of the problem let's start a new thread please. We only handle one problem per thread, please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Cheers, Ken
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Tuesday, August 29th, 2023 AT 9:50 AM
Tiny
MJ_ORIGINAL
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It's back.
Unfortunately, I can initially start and warm up the engine. Put it in Drive if I either 1)lift my foot off the pedal while making a rolling turn or 2) coast until the tachometer goes below 1000 RPMs, the Reduced Power light comes back on. If I downshift to keep it above 1K rpm, no light.
P0105 is gone.
P1514 is back.
P1345 also remains.
It's improved but not quite done.
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Tuesday, August 29th, 2023 AT 12:41 PM
Tiny
KEN L
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P1514 - Throttle Actuator Control Module Throttle Actuator Position Performance:

P1345 - Crankshaft Position-Camshaft Position Correlation (Bank 1 Sensor A):

How does the engine seem to run? I would remove the camshaft actuator oil control valve to see if there are metal shavings clogging up the passage screen. Here is the location, also we need to check the wiring connections to the throttle actuator, here is a guide and the engine wiring diagrams so you can see which wires to test.

https://www.2carpros.com/articles/how-to-check-wiring

If the valve and wiring are okay, you may have a bad PCM Check out the images (below). Please let us know how it goes.

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Wednesday, August 30th, 2023 AT 9:47 AM
Tiny
MJ_ORIGINAL
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How's it running:
-takes four cranks to start.
-check engine light is on, reduced power light is off.
-it will idle perfectly normal and then I hear a click under the hood and it gets rough but still runs. The pattern repeats itself.
-when I put it into drive it hesitates and then accelerates normally. If I take my foot off the gas or come to a stop where the idle falls below 1,200 RPM the reduced power light comes on. As long as I keep the RPMs above 1200 it drives, accelerates and cruises perfectly normal (although the cruise control will not work).
-once the reduced power light comes on I can only reset it by turning the car off for a moment and restarting.
Let me know if those details affect your advisement and it'll probably take me a couple of days before I can get back with the heat and I'm retired so I need a little extra time.
Many Thanks for your help!
The Original MJ
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Wednesday, August 30th, 2023 AT 11:39 AM
Tiny
KEN L
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It sounds like the PCM is bad to me. Can you upload a short video of the engine noise? Here is how to change the PCM out and a guide as well, you can get a preprogrammed unit by searching Google or Ebay.

Check out the images (below). Please let us know what happens.
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Thursday, August 31st, 2023 AT 10:26 AM
Tiny
MJ_ORIGINAL
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Here's two records.
1) Cold start. 4 cranks. Runs rough in spots. Check Engine Y, Reduced Power N
2) Restarting after driving on side streets and highway. I raised rpm above 1500 and when it returned to idle, Reduced Power came on and idled rougher with knocks.

Replacing variable timing solenoid. Will examine screens for blockage. If no improvement, I'll replace PCM. Thanks for the explanation/diagrams.
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Friday, September 1st, 2023 AT 3:05 PM
Tiny
MJ_ORIGINAL
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Site doesn't allow mp3 (sounds tracks).
What format is acceptable?
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Friday, September 1st, 2023 AT 3:20 PM
Tiny
KEN L
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Can you take a video with your phone, which is easier.
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Saturday, September 2nd, 2023 AT 12:40 PM
Tiny
MJ_ORIGINAL
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That's weird.
Before ordering a PMC, I wanted to finish with replacing the VVT solenoid since MAP, throttle body, cam and crankshaft sensors had all been replaced w/309K miles served.
Attached is a video of the VVT's condition.
Idles and starts smoother every time I drive it. I can hardly tell that the engine is running. Reduced Power and Engine lights are continuously off except on startup.
Thank God, and fingers crossed, it's not a timing chain/phaser assembly replacement.
Much appreciated for the resources and help along the way!
Original MJ

Ken,
for what it's worth I'm still trying to send the two recordings of the engine.
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Friday, September 15th, 2023 AT 3:27 PM
Tiny
KEN L
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Sounds good, the valve in your hand is bad, you should not be able to move the solenoid part like that. I would replace the VVT valve with a new or used unit.
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Monday, September 18th, 2023 AT 10:16 AM

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