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Canadafix
Canadafix, Canadian Class A
Category: Chevy
Satisfied Customers: 1630
Experience:  Have owned/operated an automotive repair shop for the last 19 years working on all makes and models of vehicles
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Chevrolet Silverado 2500 HD 2006 chevy 2500 hd 6.0 motor po300

Customer Question

2006 chevy 2500 hd 6.0 motor po300 code misfiring running great dont feel it at all does mostly high rpms
Submitted: 3 years ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 3 years ago.

hi

how many miles is on the truck?

has any work been done on it lately?

tell me all you can

thanks

 

Customer: replied 3 years ago.
hi 86k no work done I get on all cyc but 2-4-3-7 around 2500 rpms some say belt and reteach crank sencer some say loses crank shaft need motor
Expert:  Tim's Auto Repair replied 3 years ago.

hi

sense you dont feel the miss....

you may need to just replace the plugs and the wires...

sometimes the plug gap will get wider from heat over time..

also,you need to check the fuel pressure,these must have no less than 55psi at all tikmes,,a weak fuel pump can also cause the 300 code.................from the way you explain your problem,i think the tune up[plugs and wires] will fix the problem...

Please ACCEPT my answer by clicking the accept button, so I can get credit for my work.i don't receive commission unless you do ..I'm not always going to be giving you good news,so please don't let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.please understand,i can not see,hear or touch the vehicle and only know what you tell me. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.if i have sent any diagrams,please print them.they will only stay on here for an hour or so.PLEASE ASK IF YOU NEED MORE HELP

Customer: replied 3 years ago.
I can see one or two cylinders but4 at once
Expert:  Tim's Auto Repair replied 3 years ago.

yes,,,,,,

the wires and the plugs can do this,,,,,,,also,dont forget to check the fuel pressure,,,,low pressure can also do this

thanks

Please ACCEPT my answer by clicking the accept button, so I can get credit for my work.i don't receive commission unless you do ..I'm not always going to be giving you good news,so please don't let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.please understand,i can not see,hear or touch the vehicle and only know what you tell me. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.if i have sent any diagrams,please print them.they will only stay on here for an hour or so.PLEASE ASK IF YOU NEED MORE HELP

 

2006 Chevy Truck Silverado 2500 2WD V8-6.0L VIN U
Computers and Control Systems Testing and Inspection, Diagnostic Trouble Code Tests and Associated Procedures: P Code Charts, P0300


DTC P0300

SYSTEM DESCRIPTION
The powertrain control module (PCM) uses information from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the PCM is able to detect individual misfire events. A misfire rate that is high enough can cause the 3-way catalytic converter (TWC) to overheat under certain driving conditions. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for TWC overheating are present. If the PCM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, DTC P0300 will set.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0300 Engine Misfire Detected

CONDITIONS FOR RUNNING THE DTC
- DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0125, P0128, P0220, P0315, P0335, P0336, P0341, P0342, P0343, P0502, P0503, P1114, P1115, P1120, P1258 are not set.
- The engine speed is between 450-5,000 RPM.
- The ignition voltage is between 10-18 volts.
- The engine coolant temperature (ECT) is between -7 and +130°C (+19 and +266°F).
- The fuel level is more than 10 percent.
- The throttle angle is steady within 1 percent.
- The antilock brake system (ABS) and the traction control system (TCS) are not active.
- The transmission is not changing gears.
- The A/C clutch is not changing states.
- The PCM is not in fuel shut-off or decel fuel cut-off mode.
- The PCM is not receiving a rough road signal.
- DTC P0300 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The PCM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission levels to exceed mandated standards.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS
- Excessive vibration from sources other than the engine could cause DTC P0300 to set. The following are possible sources of vibration:
- Thickness variation of the brake rotors-Refer to Symptoms - Hydraulic Brakes in Hydraulic Brakes. See: Hydraulic System, Brakes > Symptom Related Diagnostic Procedures > Symptoms - Hydraulic Brakes
- The drive shaft not balanced-Refer to Vibration Analysis - Driveline in Vibration Diagnosis and Correction.
- Worn or damaged accessory drive belt-- There may be more or less cylinders actually misfiring than indicated by the scan tool.
- Spray water on the secondary ignition components using a spray bottle. Look and listen for arcing or misfiring.
- If there are multiple misfires on only one bank, inspect the fuel injector and ignition coil power and ground circuits for that bank.

TEST DESCRIPTION

64_06ck8pu_engi08-273.pngStep 1 - Step 7

65_06ck8pu_engi08-274.pngStep 8 - Step 20

66_06ck8pu_engi08-275.pngStep 21 - Step 23

The number below refers to the step number on the diagnostic table.
2. If the actual CKP variation values are not within the learned values, the misfire counters may increment.
Please ACCEPT my answer by clicking the accept button, so I can get credit for my work.i don't receive commission unless you do ..I'm not always going to be giving you good news,so please don't let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.please understand,i can not see,hear or touch the vehicle and only know what you tell me. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.if i have sent any diagrams,please print them.they will only stay on here for an hour or so.PLEASE ASK IF YOU NEED MORE HELP
Customer: replied 3 years ago.
Relist: Other.
know all what i was told
Expert:  Canadafix replied 3 years ago.
Hello.

I see this in my shop quite often.
If the tune up items are all in good condition then a crank-cam relearn is the fix.

The 6.0 engine is the one I see most of the time with this symptom.

It's an easy to do repair with a scan tool that has the software.
Takes about 15 minutes.
Most good repair shops should have the capability to do this.

Your questions or comments to me are welcome.

Thank you.

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Canadafix
Canadafix
Chevy Mechanic
1630 Satisfied Customers
Have owned/operated an automotive repair shop for the last 19 years working on all makes and models of vehicles