Need help!!
Pro
Joined: Feb 2021
Posts: 729
Likes: 317
From: Ashevile, NC
Before you do anything, try disconnecting the battery to reset the computer. Leave it disconnected for a few minutes then reconnect and see what happens. Don't forget to re-index the windows. If that doesn't work reach out to Dano523 with a private message. He's the go to guy for this kind of stuff.
Thread Starter
Cruising
Joined: Oct 2021
Posts: 12
Likes: 0
Before you do anything, try disconnecting the battery to reset the computer. Leave it disconnected for a few minutes then reconnect and see what happens. Don't forget to re-index the windows. If that doesn't work reach out to Dano523 with a private message. He's the go to guy for this kind of stuff.
Safety Car
Joined: Dec 2006
Posts: 4,583
Likes: 1,664
From: Pearland / Houston Tx
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.
P0641:
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
P0651:
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
• The cooling fan speed sensor
P0641:
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
P0651:
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
• The cooling fan speed sensor
Thread Starter
Cruising
Joined: Oct 2021
Posts: 12
Likes: 0
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.
P0641:
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
P0651:
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
• The cooling fan speed sensor
P0641:
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
P0651:
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
• The cooling fan speed sensor
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
I hate generic scanners with a passion since they don't get down to the body level of the car. See if anyone local has a Tech II to pull up the codes, and it should point you right at the sensor that is having the major problem in the first place.
If all items on the 5 volt reference sensors are low, then problem is at the ECM, with maybe a corroded connect at the ecm/wire gounding out somewhere, or something like a cold solder joint at the header pin that would just need to be re-soldered.
If all items on the 5 volt reference sensors are low, then problem is at the ECM, with maybe a corroded connect at the ecm/wire gounding out somewhere, or something like a cold solder joint at the header pin that would just need to be re-soldered.
Thread Starter
Cruising
Joined: Oct 2021
Posts: 12
Likes: 0
I hate generic scanners with a passion since they don't get down to the body level of the car. See if anyone local has a Tech II to pull up the codes, and it should point you right at the sensor that is having the major problem in the first place.
If all items on the 5 volt reference sensors are low, then problem is at the ECM, with maybe a corroded connect at the ecm/wire gounding out somewhere, or something like a cold solder joint at the header pin that would just need to be re-soldered.
If all items on the 5 volt reference sensors are low, then problem is at the ECM, with maybe a corroded connect at the ecm/wire gounding out somewhere, or something like a cold solder joint at the header pin that would just need to be re-soldered.
Thread Starter
Cruising
Joined: Oct 2021
Posts: 12
Likes: 0
I hate generic scanners with a passion since they don't get down to the body level of the car. See if anyone local has a Tech II to pull up the codes, and it should point you right at the sensor that is having the major problem in the first place.
If all items on the 5 volt reference sensors are low, then problem is at the ECM, with maybe a corroded connect at the ecm/wire gounding out somewhere, or something like a cold solder joint at the header pin that would just need to be re-soldered.
If all items on the 5 volt reference sensors are low, then problem is at the ECM, with maybe a corroded connect at the ecm/wire gounding out somewhere, or something like a cold solder joint at the header pin that would just need to be re-soldered.
Safety Car
Joined: Aug 2017
Posts: 4,924
Likes: 2,334
From: Etobicoke (Toronto) Ontario
1) The fob needs to be oriented correctly in the slot: key ring end facing out, and buttons facing passenger side.
2) Do you have a second fob and did you try that one?
3) Do any of fob buttons work, such as lock and unlock?
2) Do you have a second fob and did you try that one?
3) Do any of fob buttons work, such as lock and unlock?