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I've put a 2009 vortec 6 liter in 83 chevy with a new wiring…

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I've put a 2009 vortec...
I've put a 2009 vortec 6 liter in 83 chevy with a new wiring harness. everything was fine till one day it idled down and throttlebody butterfly wouldn't open. Shut off and ten minutes later starts and runs fine for a while. Replaced pedal and throttle body. No help. Codes po641,po650 and po300. Any ideas?
Submitted: 10 months ago.Category: Chevy
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9/21/2017
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago
Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 7,887
Experience: ASE master tech for 40 years
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hello, my name is ***** ***** I will be glad to assist you. please allow me a couple of minutes to gather some basic info.

Roy

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Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

does the check engine light work??

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Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

641 below

did you verify voltage to the tps sensor??

DTC P0641 or P0651

Diagnostic Instructions

* Perform theDiagnostic System Check - Vehicle (See: Vehicle > Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Strategy Based Diagnosis (See: Vehicle > Initial Inspection and Diagnostic Overview)for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Vehicle > Initial Inspection and Diagnostic Overview)provide an overview of each diagnostic category.

DTC Descriptors
DTC P0641
- 5-Volt Reference 1 Circuit

DTC P0651
- 5-Volt Reference 2 Circuit

Diagnostic Fault Information

Zoom/Print

Circuit/System Description

The engine control module (ECM) has 2 internal 5-volt reference busses called 5-volt reference 1 and 5-volt reference 2. Each reference bus provides 5-volt reference circuits for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to that reference bus. The ECM monitors the voltage on the 5-volt reference busses.

The 5-volt reference 1 bus provides 5 volts to the following sensors:

* The manifold absolute pressure (MAP) sensor
* The fuel tank pressure (FTP) sensor
* The air conditioning (A/C) refrigerant pressure sensor
* The accelerator pedal position (APP) sensor 2
* The engine oil pressure (EOP) sensor
* The camshaft position (CMP) sensor

The 5-volt reference 2 bus provides 5 volts to the following sensors:

* The APP sensor 1
* The throttle position (TP) sensor 1 and 2
* The crankshaft position (CKP) sensor

Conditions for Running the DTC

* The ignition is in Unlock, Accessory, Run, or Crank.
* The ignition voltage is more than 5.23 volts.
* DTCs P0641 and P0651 run continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects a voltage out of tolerance condition on the 5-volt reference 1 or 2 bus for more than 0.5 second.

Action Taken When the DTC Sets

DTCs P0641 and P0651 are Type A DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0641 and P0651 are Type A DTCs.

Reference Information
Schematic Reference

Engine Controls Schematics (See: Powertrain Management > Electrical)
Connector End View Reference

Component Connector End Views (See: Vehicle > Connector Views)
Electrical Information Reference

* Circuit Testing (See: Vehicle > Component Tests and General Diagnostics)
* Connector Repairs (See: Vehicle > Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (See: Vehicle > Component Tests and General Diagnostics)
* Wiring Repairs (See: Vehicle > Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (See: Vehicle > Programming and Relearning)for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool 5-volt reference 1 and 2 parameters. The reading should display Circuit OK for a normally operating system.

Circuit/System Testing

Important: Additional DTCs may set when disconnecting components.

1. Ignition OFF, disconnect the harness connector of all the sensors connected to the 5-volt reference bus for the applicable DTC. Refer to Circuit/System Description.

Important: A short to voltage on the signal circuit of certain components may cause this DTC to set.

2. Ignition ON, test for 4.8-5.2 volts between one of the 5-volt reference circuits and ground.

♦ If less than the specified range, test all of the 5-volt reference circuits for a short to ground. If all circuits test normal, replace the ECM.
♦ If greater than the specified range, test for a short to voltage on all of the 5-volt reference circuits, or the signal circuit for each component associated with the appropriate 5-volt reference bus for a short to voltage. If all circuits test normal, replace the ECM.

3. Connect each component associated with the appropriate 5-volt reference bus, one at a time, while monitoring the voltage. The voltage should not change more than 1 volt.

♦ If the voltage display changes more than the specified range when a component is connected, replace the component.

Repair Instructions

Perform theDiagnostic Repair Verification (See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests) after completing the diagnostic procedure.

* Accelerator Pedal Position Sensor Replacement (See: Accelerator Pedal Position Sensor > Removal and Replacement)
* Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (Non-HP2) (See: Refrigerant Pressure Sensor / Switch, HVAC > Removal and Replacement > Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement)
* Fuel Tank Pressure Sensor Replacement (Regular Cab w/34 Gal Tank) (See: Fuel Tank Pressure Sensor > Removal and Replacement)Fuel Tank Pressure Sensor Replacement (Regular Cab w/26 Gal Tank) (See: Fuel Tank Pressure Sensor > Removal and Replacement)Fuel Tank Pressure Sensor Replacement (Extended Cab w/26 Gal Tank) (See: Fuel Tank Pressure Sensor > Removal and Replacement)
* Manifold Absolute Pressure Sensor Replacement (See: Manifold Pressure/Vacuum Sensor > Removal and Replacement)
* Throttle Body Assembly Replacement (See: Throttle Body > Removal and Replacement > Throttle Body Assembly Replacement)
* Engine Oil Pressure Sensor and/or Switch Replacement (See: Oil Pressure Sensor > Removal and Replacement)
* Camshaft Position Sensor Replacement (See: Camshaft Position Sensor > Removal and Replacement)
* Crankshaft Position Sensor Replacement (See: Crankshaft Position Sensor > Removal and Replacement)
* Control Module References (See: Vehicle > Programming and Relearning)for ECM replacement, setup, and programming

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Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

did you perform the throttle re learn after replacing the throttle body???

if not the procedure is below

Roy

Without Scan Tool - Learn Procedure

Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions) .

1. Start and idle the engine in PARK for 3 minutes.
2. With a scan tool, monitor desired and actual RPM.
3. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
4. Ignition OFF for 60 seconds.
5. Start and idle the engine in PARK for 3 minutes.
6. After the 3 minute run time the engine should be idling normal.

Important: During the drive cycle the check engine light may come on with idle speed DTCs. If idle speed codes are set, clear codes so the ECM can continue to learn.

♦ If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 km/h (44 mph) with several decelerations and extended idles.

7. After the drive cycle, the engine should be idling normally.

♦ If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds and repeat step 6.

8. Once the engine speed has returned to normal, clear DTCs and return to the diagnostic that referred you here.

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Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

650

DTC P0650

Diagnostic Instructions

* Perform theDiagnostic System Check - Vehicle (See: Vehicle > Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Strategy Based Diagnosis (See: Vehicle > Initial Inspection and Diagnostic Overview)for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Vehicle > Initial Inspection and Diagnostic Overview)provide an overview of each diagnostic category.

DTC Descriptor
DTC P0650
- Malfunction Indicator Lamp (MIL) Control Circuit

Diagnostic Fault Information

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Circuit/System Description

The malfunction indicator lamp (MIL) is located on the instrument panel cluster (IPC).

The MIL informs the driver that an emission system fault has occurred and that the engine control system requires service. The control module monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL.

Conditions for Running the DTC

* The ignition is in the Run or Crank position.
* The ignition voltage is between 9-18 volts.
* DTC P0650 runs continuously when the ignition is ON.

Conditions for Setting the DTC

The control module detects that the commanded state of the MIL driver and the actual state of the control circuit do not match for more than 5 seconds.

Action Taken When the DTC Sets

DTC P0650 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0650 is a Type B DTC.

Reference Information
Schematic Reference

* Instrument Cluster Schematics (See: Instrument Panel, Gauges and Warning Indicators > Electrical > Instrument Cluster Schematics)
* Engine Controls Schematics (See: Powertrain Management > Electrical)

Connector End View Reference

Component Connector End Views (See: Vehicle > Connector Views)
Electrical Information Reference

* Circuit Testing (See: Vehicle > Component Tests and General Diagnostics)
* Connector Repairs (See: Vehicle > Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (See: Vehicle > Component Tests and General Diagnostics)
* Wiring Repairs (See: Vehicle > Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (See: Vehicle > Programming and Relearning)for scan tool information

Circuit/System Verification

Ignition ON, the MIL should turn ON and OFF when commanded with a scan tool.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the IPC.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit and ground.

♦ If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the IPC.

3. Connect a test lamp between the control circuit and the ignition circuit.
4. Command the MIL ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

♦ If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
♦ If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

5. If all circuits test normal, replace the IPC.

Repair Instructions

Perform theDiagnostic Repair Verification (See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests) after completing the diagnostic procedure.

* Control Module References (See: Vehicle > Programming and Relearning)for ECM replacement, setup, and programming
* Instrument Cluster Replacement (Without RPO SLT) (See: Instrument Cluster / Carrier > Removal and Replacement > Instrument Cluster Replacement (Without RPO SLT))Instrument Cluster Replacement (With RPO SLT) (See: Instrument Cluster / Carrier > Removal and Replacement > Instrument Cluster Replacement (With RPO SLT))

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Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

the 300 is a random missfire on all cylinders. I would verify fuel pressure first before doing anything.

Roy

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Customer reply replied 10 months ago
Would any of these cause the engine to idle down?
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

the throttle re learn not being done, yes

no throttle response would be from missing 5 volt reference.

did you verify voltage to the tps???

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Customer reply replied 10 months ago
It was doing this prior to changing pedal. It idles and runs fine for a while then idled down.after few minutes runs fine again. Does everything have to be grounded
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

ok, again, did you verify voltage to the tps sensor???

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Customer reply replied 10 months ago
Does ecm need to be grounded
Customer reply replied 10 months ago
I did not How?
Customer reply replied 10 months ago
Do I check voltage in plug to throttle body
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

yes it does and it is otherwise it would not run at all

you need a voltmeter to test for the voltage.

you unplug the connector and check the voltage with the key on

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Customer reply replied 10 months ago
The ecm has not been grounded and it was running and runs now but I'll ground it. Do I unplug plug at throttlebody and check all connectors with voltmeter with key on. The wiring harness had a ground wire going from ecm
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

there are computer grounds in the connectors for the ecm. if it was not grounded it would not run.

yes, with key on. tell me what wires have voltage

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Customer reply replied 10 months ago
Can I resume this tomorrow. I am not at ��
Customer reply replied 10 months ago
Am not at ��
Customer reply replied 10 months ago
Am not at vehicle
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

ok

Please take a moment and rate my service 5 stars so the site will pay me for my efforts. We only get paid when you accept our answers

Roy

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Customer reply replied 10 months ago
Can I resume tomorrow
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

yep anytime

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Customer reply replied 10 months ago
Checked voltage center pin on bottom 5.07 next pin 4.15 volts
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

ok, the third wire is a ground. re check one of the powers while using the 3rd pin as a ground to verify the ground

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Customer reply replied 10 months ago
Looking at plug 3 prongs on top and three on bottom. Center bottom to right. Bottom 4.11 center bottom to top left 5.01 to top center 4.47 top right 4.47
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

correct. the last 2 are grounds

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Customer reply replied 10 months ago
This is lower voltage than straight to battery ground. Is this normal
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

yep, it needs reference voltage. around 5 volts

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Customer reply replied 10 months ago
this is not problem
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

still waiting for you to retest to verify the grounds

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Customer reply replied 10 months ago
I did. Voltage at plug to ground on plug was on answer above
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

ok did not realize that. sorry

ok we have the needed powers there.

next is the pedal sensor. do the same checks inside the truck at the pedal sensor

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Customer reply replied 10 months ago
Pedal sensor 4.9 volts
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

did you check the grounds the same as outside???

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Customer reply replied 10 months ago
From center to both ends 5 .01 volts
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

good.

ok, you need to do the throttle relearn I posted and see if that helps it. otherwise we are looking at either the throttle body or pedal assembly.

were they new GM parts???

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Customer reply replied 10 months ago
Pedal and throttlebody are both new. Was doing it before I changed them
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

you can still have a bad new part

are the GM

did you do the throttle re learn yet??

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Customer reply replied 10 months ago
The part was gm. It idles normally
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

do you have a scan tool that can read live data for the tps???

Roy

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Customer reply replied 10 months ago
No I do not
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

at this point that is what you need to monitor the live data from both the pedal sensor and tps to determine where the failure is located.

can you get one?? call parts stores and see if you can rent one.

Roy

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Customer reply replied 10 months ago
Local mechanic said the plug on throttlebody gives trouble. Was new with wiring harness. ???
Chevy Mechanic: Roy, import/domestic specialest replied 10 months ago

the end should have come with the throttle body.

yes, it is common for being an issue. it is a pigtail that should have come with the throttle body

Roy

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Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

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