Electrical system......need help
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Instructor
Joined: Apr 2002
Posts: 121
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From: Vancouver
Electrical system......need help
Today when I started up my 93 vette,The service engine light came on and stayed on for about 10 mins while driving,Later in the afternoon im sitting at alight and the car just dies on me....the battery light and then charging system light come on. so I try to start my car doesent start until i try starting it with the gas pedal half way down....finally it starts and then dies again......so I do the same thing again.....turn the key and press the gas pedal, it starts up after a few seconds so this time i rev it up a bit and now its just idleing so I take off and it works perfect till I get home............... I bought the car 2 weeks ago......It had new starter put in recently....The battery looks very old......so I think that will need replacing.......could it just be the battery? or is it somthing to do with the plugs and wires....any help would be apreciated....thanks Todd
Racer
Joined: Jan 2001
Posts: 425
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From: Frederick MD
Re: Electrical system......need help (Todd15)
Might want to get someone with a scanner to see if the computer is throwing any trouble codes since you had an SES light. Check the voltage on the battery with a multi-meter. Check battery terminal and cables for corrosion. But if you just had the starter replaced, you might want to take it back to the garage where that was done and have them recheck their work.
Melting Slicks
Joined: Apr 2002
Posts: 2,546
Likes: 0
From: Orlando FL
Re: Electrical system......need help (Todd15)
That is a tough call.. I would check the engine codes first on the car. This might help narrow the problem. No sense just replacing stuff because anybody can through money at a car.. just gotta make sure its the right thing..
http://www.c4vettes.com/ecm.htm follow that site.. It will lead you through the steps to get the engine code.. Once you get a code, post back on here an someone should be able to help.. that or IM me.. Good luck :blueangel:
http://www.c4vettes.com/ecm.htm follow that site.. It will lead you through the steps to get the engine code.. Once you get a code, post back on here an someone should be able to help.. that or IM me.. Good luck :blueangel:
Team Owner
Joined: Oct 2000
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St. Jude Donor '03-'04
Cruise-In 1-2-3-4-5 Veteran
Re: Electrical system......need help (Todd15)
What doesn't make sense?
DTC 24 - Vehicle Speed Sensor Circuit
DTC 34 - Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage Low / High Vacuum)
'93s have MAP sensors.
"If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery."
DTC 34 will set when:
MAP less than 20 kPa and RPM less than 700 RPM, or
MAP less than 20 kPa, RPM greater than 700 RPM, and TP sensor greater than 20%
An intermittent open circuit 432 or 416 will set a 34.
Basically, you need a scan tool, or at least a multimeter, to trouble shoot. Or you can buy a new MAP sensor. Or your ECM is shot, or your wiring harness is shot between the ECM and the MAP.
DTC 24 - Vehicle Speed Sensor Circuit
DTC 34 - Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage Low / High Vacuum)
'93s have MAP sensors.
"If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery."
DTC 34 will set when:
MAP less than 20 kPa and RPM less than 700 RPM, or
MAP less than 20 kPa, RPM greater than 700 RPM, and TP sensor greater than 20%
An intermittent open circuit 432 or 416 will set a 34.
Basically, you need a scan tool, or at least a multimeter, to trouble shoot. Or you can buy a new MAP sensor. Or your ECM is shot, or your wiring harness is shot between the ECM and the MAP.
Melting Slicks
Joined: Apr 2002
Posts: 2,546
Likes: 0
From: Orlando FL
Re: Electrical system......need help (Matt Black)
What doesn't make sense?
DTC 24 - Vehicle Speed Sensor Circuit
DTC 34 - Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage Low / High Vacuum)
'93s have MAP sensors.
"If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery."
DTC 34 will set when:
MAP less than 20 kPa and RPM less than 700 RPM, or
MAP less than 20 kPa, RPM greater than 700 RPM, and TP sensor greater than 20%
An intermittent open circuit 432 or 416 will set a 34.
Basically, you need a scan tool, or at least a multimeter, to trouble shoot. Or you can buy a new MAP sensor. Or your ECM is shot, or your wiring harness is shot between the ECM and the MAP.
DTC 24 - Vehicle Speed Sensor Circuit
DTC 34 - Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage Low / High Vacuum)
'93s have MAP sensors.
"If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery."
DTC 34 will set when:
MAP less than 20 kPa and RPM less than 700 RPM, or
MAP less than 20 kPa, RPM greater than 700 RPM, and TP sensor greater than 20%
An intermittent open circuit 432 or 416 will set a 34.
Basically, you need a scan tool, or at least a multimeter, to trouble shoot. Or you can buy a new MAP sensor. Or your ECM is shot, or your wiring harness is shot between the ECM and the MAP.
