P2646 Tested and tested still nothing
#1
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P2646 Tested and tested still nothing
2004 Civic ex 157,000 miles, Drives fine after initial start up. Once i reach 45-50 mph the ecu goes into limp mode. Wont go passed 3800 rpms if i shut the car off whiling driving and restart it, its fine for a while.
So I have checked:
oil level-clean and full
vtec solenoid - Opens and closes when power is applied
Vtec screen - clean
oil pressure- is within spec
wiring- good
Please help me out
So I have checked:
oil level-clean and full
vtec solenoid - Opens and closes when power is applied
Vtec screen - clean
oil pressure- is within spec
wiring- good
Please help me out
#2
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Re: P2646 Tested and tested still nothing
Disconnect the VTEC oil pressure sensor and measure the sensor for continuity @ 3000rpm
no continuity @ 3000rpm or continuity below 3000rpm= bad oil pressure switch
continuity @ 3000rpm= short in the wires between the sensor and the ECM/PCM
no continuity @ 3000rpm or continuity below 3000rpm= bad oil pressure switch
continuity @ 3000rpm= short in the wires between the sensor and the ECM/PCM
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Re: P2646 Tested and tested still nothing
Oil pressure switch is operating fine. Switched it out with one that works fine on another 04 civic. Same problem.
#6
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Re: P2646 Tested and tested still nothing
1. Disconnect battery terminals from the VTEC solenoid connector and disconnect ECM/PCM connector B (connector B is the second from the bottom while you're looking at the ECM/PCM in the dash)
2. Check for continuity between ECM/PCM connector terminal B9 (blue/black) and body ground
Is there continuity?
Yes- Repair the short in the wire between B9 and the oil pressure switch
NO- next step
3. Check for continuity between ECM/PCM connector terminal B15 (green/yellow) and body ground
Is there continuity?
YES- Repair the short in the wire between B15 and the VTEC solenoid
NO- nect step
4. At the solenoid valve connector, jump a wire from the harness side of the connector to body ground
5. Check for continuity between B15 and body ground
Is there continuity?
YES- update or replace ECM/PCM
NO- repair open between B15 and the solenoid
2. Check for continuity between ECM/PCM connector terminal B9 (blue/black) and body ground
Is there continuity?
Yes- Repair the short in the wire between B9 and the oil pressure switch
NO- next step
3. Check for continuity between ECM/PCM connector terminal B15 (green/yellow) and body ground
Is there continuity?
YES- Repair the short in the wire between B15 and the VTEC solenoid
NO- nect step
4. At the solenoid valve connector, jump a wire from the harness side of the connector to body ground
5. Check for continuity between B15 and body ground
Is there continuity?
YES- update or replace ECM/PCM
NO- repair open between B15 and the solenoid
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Re: P2646 Tested and tested still nothing
ok so i tested the wiring everything is fine there. the only time i have continuity is if b plug is plugged into the ecm.... my next step i think is to pull the valve cover and inspect the rocker arm assembly. i have heard there is a bolt/plug that goes in the head so a tech can check the oil pressure on the other side of the vtec solenoid.....
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Re: P2646 Tested and tested still nothing
soo after looking at the rocker assembly i found the problem!!!!! the cars head gasket had been change by some one almost a year ago.. they torqued the head correctly but no the cam caps. i found 3 lose bolts which would allow the cam caps to move away from the cam...this is what cuzed the oil pressure to lower enough to through a code. tightened the bolts and no more problems all day!!!
Thanks lazlong for your help.
Thanks lazlong for your help.
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