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AMEDEE
AMEDEE, CHEVY TECHNICIAN
Category: Chevy
Satisfied Customers: 24432
Experience:  ASE certified tech ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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I had to jump start it, and now it won't start and have a

Customer Question

I had to jump start it, and now it won't start and have a code of po621?
JA: Will the headlights turn on? Is the battery fully charged?
Customer: Headlights come on, I replaced the battery
JA: What is the model/year of your Chevy?
Customer: 2001 s 10 2.2 liter engine
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Yes I'd like to, I've checked all the fuses and had to replaced a couple that were blowed after I installed the new battery
JA: Anything else you want the mechanic to know before I connect you?
Customer: No I guess not
Submitted: 2 months ago.
Category: Chevy
Expert:  AMEDEE replied 2 months ago.

Hello and welcome!

My name isCustomerand I can assist you with your question.

Expert:  AMEDEE replied 2 months ago.

Does the engine crank over and not start or does it not crank over at all? Does the check engine light come on with thek ey on?

Expert:  AMEDEE replied 2 months ago.

Are you looking for possible causes or would you like me to walk you through this diagnoses?

Customer: replied 2 months ago.
It does crank but won't start, it has a code of po621, I'd like a solution to fix it?
Customer: replied 2 months ago.
How likely is it that it is the Ecm?
Customer: replied 2 months ago.
Check engine light is on when I crank it and the code I mentioned is the only code in it
Expert:  AMEDEE replied 2 months ago.

This P0621 code is for an internal failure inside the ECM. YES, it is very likley the ECM is at fault causing this code. However, it may or may not be related to the starting issue you are having. I would check for power at the ignition switch and the complete starting circuit (and ignition switch) to ensure the starting circuit is working like it should before replacing any components.

Customer: replied 2 months ago.
The old battery shorted out so I put a new one in and it hasn't stated since, how would I check the ignition switch, I've checked all the fuses and they are good and have power including the Ecm fuses and ignition fuses
Expert:  AMEDEE replied 2 months ago.

You can use a test light or a voltmeter to check the starting circuit. I can send you a wiring diagram to help with this. Are you sure there are no anti theft or security lights on or flashing on the dash?

Customer: replied 2 months ago.
No it's just a basic LS model s10 no anti theft devices
Expert:  AMEDEE replied 2 months ago.

Ok, I would start at the starter relay. Check for two power and one ground going into the relay with the key in the CRANK position. You would do this with the relay removed checking the female pins for voltage. Here is a wiring diagram of your starting circuit.

Customer: replied 2 months ago.
Any other suggestions?
Expert:  AMEDEE replied 2 months ago.

Sorry, you said it cranks but does not start?

Customer: replied 2 months ago.
Expert:  AMEDEE replied 2 months ago.

I am sorry about that. Then we need to check for spark and or fuel when cranking. Have you verified that the engine has spark while cranking?

Customer: replied 2 months ago.
How would I do that?
Expert:  AMEDEE replied 2 months ago.

You can use a spark tester or a screw driver. Just gain access to the spark plug wire and remove it from the spark plug and insert the spark tester. YES, if there is no spark and all fuses are good, it could be a bad ECM.

Customer: replied 2 months ago.
Ok, the Ecm and pcm are the same thing on this model truck right?
Expert:  AMEDEE replied 2 months ago.

YES, they are pretty close. One controls the transmission and the other one does not. Yours is actually a PCM.

Customer: replied 2 months ago.
Ok it's a manual transmission
Expert:  AMEDEE replied 2 months ago.

Ok, then it is the ECM

Expert:  AMEDEE replied 2 months ago.

I am glad I can help!

It has been a pleasure working with you. Please dont forget to honor your good faith deposit by rating my answer as "5 STAR SERVICE" for assisting you today.

Please let me know if you have any further questions.

Expert:  AMEDEE replied 2 months ago.

Hello! It'sCustomerfrom just answer.

I am just checking in to see if you need any further assistance?

Let me know!

Expert:  AMEDEE replied 2 months ago.

Hello!

Just checking in to see if you need any further help or if you have any further questions?

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