LSA Swap question (pics)
02-05-2017, 08:49 PM
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Teching In
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LSA Swap question (pics) I put a LSA from a wrecked car in my 67 nova. I bought a GMPP computer and harness i fit like total crap so i got a custom harness. So its in and Jeremy Formato put a tune in it for the 96lb injectors and added boost it has a cam and headers with 3" exhaust with no cats. So it starts runs for a sec or 2 quits and wont start again until you undo the battery. Then it starts again 1 time and then wont start. It wont rev and i cant seem to get the pedal to work. The codes are po512 and po651 i googled them but i dont understand what they do or how to fix it. Any ideas???
02-08-2017, 11:28 PM
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•P0512 - Start Switch Circuit
•P0651 - PCM voltage out of tolerance condition on the 5-volt reference circuit
Sounds like something on the ignition system isn't connected. Are you logging this as you are cranking? I wonder if you are seeing a RPM signal while cranking.
•P0651 - PCM voltage out of tolerance condition on the 5-volt reference circuit
Sounds like something on the ignition system isn't connected. Are you logging this as you are cranking? I wonder if you are seeing a RPM signal while cranking.
02-27-2017, 12:16 PM
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it starts for 1 sec then it dies and wont start till you disconnect the battery and re connect it. Then it starts 1 time again. I have a data log for the start and 1 sec of run time but i dont know what im looking at can anyone help me? pm me ill email it to you
02-28-2017, 11:47 PM
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Codes and no start P0512 doesn't usually exist as a code on the 2009-2015 LSA equipped production vehicles or most other newer GM vehicles that I am familiar with (I assume this is because the starter switch is often no longer wired directly to the ECM so it is monitored by other diagnostic codes instead).
P0512 does exist on the GMPP calibrations though.
Is this ECM and software set from the GMPP crate engine ECM?
You mention you had the GMPP harness and then had a custom harness made, is that correct?
The GMPP ECM is designed to plug into the GMPP harness. If you put the GMPP ECM in an OEM harness (in a standard vehicle for example) the GMPP ECM will not let the engine start. This is done so that the GMPP ECM can't be used as a bypass for the Federal vehicle anti-theft requirements.
Not 100% sure but if your harness is more like a factory vehicle harness this may be the cause of the codes and no start condition.
Otherwise it could be a wiring error, possibly one that either pulls the 5 volt low or applies 12 volt where it doesn't belong.
DTC P06515 is related to the 5 volt reference on Circuit 2.
Here is the GM diagnostic information for that code:
P0512 does exist on the GMPP calibrations though.
Is this ECM and software set from the GMPP crate engine ECM?
You mention you had the GMPP harness and then had a custom harness made, is that correct?
The GMPP ECM is designed to plug into the GMPP harness. If you put the GMPP ECM in an OEM harness (in a standard vehicle for example) the GMPP ECM will not let the engine start. This is done so that the GMPP ECM can't be used as a bypass for the Federal vehicle anti-theft requirements.
Not 100% sure but if your harness is more like a factory vehicle harness this may be the cause of the codes and no start condition.
Otherwise it could be a wiring error, possibly one that either pulls the 5 volt low or applies 12 volt where it doesn't belong.
DTC P06515 is related to the 5 volt reference on Circuit 2.
Here is the GM diagnostic information for that code:
Circuit/System Description
The engine control module (ECM) has 2 internal 5 V reference circuits. Each internal reference circuit provides a 5 V reference for more than one sensor. A short to ground or short to voltage on one of the external 5 V reference circuits can affect all the components connected to the same internal 5 V reference circuit.
Conditions for Running the DTC
•Reduced Engine Power is not active.
•The ignition is ON.
•The ignition voltage is greater than 6 V.
•DTCs P0641 and P0651 run continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects a voltage out of tolerance condition on the 5 V reference 1 or 2 circuit for greater than 0.5 s.
The 5 V reference 2 circuit provides 5 V to the following sensors:
– APP sensor 1
– Throttle position sensor 1 and 2
– Crankshaft position sensor
– Clutch pedal position sensor, if equipped
•It may be possible to locate the fault by disconnecting one component at a time from the affected 5 V reference circuit while viewing the 5 V Reference Circuit Status parameter on the scan tool. The scan tool parameter will change from Fault to OK when the source of the fault is disconnected. If all 5 V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.
You mention you have a data log. What software are you using to log the ECM? Are you able to use that tool to also tell you the calibration ID's (segment numbers) for the calibration in your ECM?The engine control module (ECM) has 2 internal 5 V reference circuits. Each internal reference circuit provides a 5 V reference for more than one sensor. A short to ground or short to voltage on one of the external 5 V reference circuits can affect all the components connected to the same internal 5 V reference circuit.
Conditions for Running the DTC
•Reduced Engine Power is not active.
•The ignition is ON.
•The ignition voltage is greater than 6 V.
•DTCs P0641 and P0651 run continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects a voltage out of tolerance condition on the 5 V reference 1 or 2 circuit for greater than 0.5 s.
The 5 V reference 2 circuit provides 5 V to the following sensors:
– APP sensor 1
– Throttle position sensor 1 and 2
– Crankshaft position sensor
– Clutch pedal position sensor, if equipped
•It may be possible to locate the fault by disconnecting one component at a time from the affected 5 V reference circuit while viewing the 5 V Reference Circuit Status parameter on the scan tool. The scan tool parameter will change from Fault to OK when the source of the fault is disconnected. If all 5 V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.
