No Signal for Starter
10-25-2017, 09:48 AM
#1
No Signal for Starter Hey Guys, winding down my build and just trying to work out some final kinks.
It started life as a LS1 6 speed car, purchased as a roller and now is a LS1/4L60e car, and i think that may be were some of my problems lie. The PCM is a Auto PCM, the engine harness is an auto harness, however the body harness is a modified 6 speed one.
First thought is my problem lies with the wiring to adapt the clutch switch, starter relay coil or neutral safety to work with the 6 pin A4 shifter plug. All info on this wiring can be found in my thread here
https://ls1tech.com/forums/automatic...ification.html
Anyways, heres the issue
The starter itself is getting power, the relay is getting power, but there is no signal to the relay when the key is turned. To get the car started as a test, i just used a piece of wire to jump the relay. Car started right up. That proved that the ignition relay was a good relay, so i swapped that with the starter relay to see if maybe it was just a bad starter relay, and still nothing.
Anyone ever run into any issues like this ?
It started life as a LS1 6 speed car, purchased as a roller and now is a LS1/4L60e car, and i think that may be were some of my problems lie. The PCM is a Auto PCM, the engine harness is an auto harness, however the body harness is a modified 6 speed one.
First thought is my problem lies with the wiring to adapt the clutch switch, starter relay coil or neutral safety to work with the 6 pin A4 shifter plug. All info on this wiring can be found in my thread here
https://ls1tech.com/forums/automatic...ification.html
Anyways, heres the issue
The starter itself is getting power, the relay is getting power, but there is no signal to the relay when the key is turned. To get the car started as a test, i just used a piece of wire to jump the relay. Car started right up. That proved that the ignition relay was a good relay, so i swapped that with the starter relay to see if maybe it was just a bad starter relay, and still nothing.
Anyone ever run into any issues like this ?
10-25-2017, 12:51 PM
#4
There is power at the 85 and 30 pin of the relay, 87 goes to the starter, 86 goes to the BCM, which is the ground.
So what it looks like, to me atleast, the key isnt grounding out the relay. Thus no complete circuit.
However if were to ground out the 86 pin, would that render it on at all times?
So what it looks like, to me atleast, the key isnt grounding out the relay. Thus no complete circuit.
However if were to ground out the 86 pin, would that render it on at all times?
10-25-2017, 06:03 PM
#5
There is power at the 85 and 30 pin of the relay, 87 goes to the starter, 86 goes to the BCM, which is the ground.
So what it looks like, to me atleast, the key isnt grounding out the relay. Thus no complete circuit.
However if were to ground out the 86 pin, would that render it on at all times?
So what it looks like, to me atleast, the key isnt grounding out the relay. Thus no complete circuit.
However if were to ground out the 86 pin, would that render it on at all times?
10-26-2017, 06:30 AM
#6
Pins 85 and 86 control the coil of the relay which closes the contact of the relay to energize the starter solenoid. If you were to ground pin 86, the relay would stay energized as long as the pin was grounded. I'm not familiar with HP Tuner software, but is it possible only the fuel pump enable was bypassed? The start enable is the ground path through the BCM to coil of the start relay and if the bypass didn't include enabling this operation, that could explain what you're experiencing.
If it is the VATS, i should be able to bypass with a resistor then, correct?
10-26-2017, 05:55 PM
#7
After looking at the attached diagram, I would think HP Tuner software may be able to bypass the BCM signal to enable the starter relay just like the fuel pump. Doing the VATS bypass should accomplish the same result as the software bypass.
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10-30-2017, 09:38 AM
#8
No, it is impossible to completely tune out VATS with HP Tuner or any similar program. You can program the PCM to ignore the missing fuel enable signal from the BCM (where VATS is) but the BCM is not programmable and VATS physically controls the ground signal for the starter relay coil in the BCM. Yes, you could do a VATS bypass with resistors but in this case it would be easier to simply provide a constant ground for the starter relay coil so that the BCM no longer controls it. All that's necessary is to cut the yellow/black wire under the starter relay socket and connect the relay end of the wire to a good chassis ground.
11-03-2017, 12:45 PM
#10
No, it is impossible to completely tune out VATS with HP Tuner or any similar program. You can program the PCM to ignore the missing fuel enable signal from the BCM (where VATS is) but the BCM is not programmable and VATS physically controls the ground signal for the starter relay coil in the BCM. Yes, you could do a VATS bypass with resistors but in this case it would be easier to simply provide a constant ground for the starter relay coil so that the BCM no longer controls it. All that's necessary is to cut the yellow/black wire under the starter relay socket and connect the relay end of the wire to a good chassis ground.
I've seen vendors and site sponsors advertise vats delete.
You can not delete vats from the BODY Control module, or from an Fbody. Drives me crazy people asking some one to tune it out of their fbody