PRNDL need Disabled for auto to manual swap?

[Mobile Chassis Dyno]

OS - 12216215

2002 Silverado.

4L60E to Manual Trans swap.


Did a bench tune for the customer. Set the trans from 4L60E to Manual. Customer is getting a no start. He is telling me the truck thinks its in gear. Is it not starting because because of a lack of neutral safety switch on the clutch pedal? Will setting the PRNDL to none resolve this? I have never ran into this before with any F body OS's using a Turbo 350 or Turbo 400 trans.

[ElecTech]

From memory, the ECU could care less what gear it's in for starting. The neutral safety is a physical layer safety device, not ECU dependent. The selector function is to allow the ECU to work in the appropriate tables. Manual ECUs work out of the Drive tables anyway. They have a VATS issue or ECU is loosing voltage after cranking or it just doesn't want to run for any number of reasons.

You can try changing the settings and see. Set it how a manual is set. Is he running a manual? On TH350 swaps I like to leave them as auto files and ad a selector switch for better drivability characteristics.

[MikeOD]

I don't think the PCM cranks the starter on the 2002 trucks...on the 2003+ trucks it does (you can let go of the key and the starter will continue to crank for a certain time or until the engine fires).

If it's not even cranking the starter, he's probably got an electrical issue or a VATS issue.

[MikeOD]

Actually, I think the range selector switch (the switch that tells the truck where the driver has the shifter in an auto truck) is on the automatic transmission...so the BCM, starter relay...everything...may be locked out because it thinks the vehicle is in gear...but that's not really a PCM thing. If the switch was just unplugged and nothing was done with the wires, it thinks it's in gear...if you connect them to each other, it will think it's in park or neutral...that's how I always had to do it when swapping LT1 Caprices and Impala's from auto to manual...run those 2 wires to the clutch pedal neutral safety switch, then everything worked correctly).

If I remember correctly, there is a pair of wires from that switch that needs to be run to the clutch pedal safety switch instead...this will allow the truck to crank the starter when the clutch pedal is down, and prevent it from cranking it when it's not down. The same switch also probably has the wires that need to connect to the reverse light switch on the manual transmission to let them work again.

[Montecarlodrag]

Don't mess with the PRNDL or auto/manual settings in the tune, some weird combinations cause a no-start.
Just delete all the DTCs for auto trans and it will work good.
The best option would be to flash a manual tune, If you want I can check to see if I have one you can use.

[ota21mvt]

Don't mess with the PRNDL or auto/manual settings in the tune, some weird combinations cause a no-start.
Just delete all the DTCs for auto trans and it will work good.
The best option would be to flash a manual tune, If you want I can check to see if I have one you can use.

I have an R5R30A manual in my lm7 swapped volvo.
has a p01 2002 suburban pcm that matches the engine.
Previous owner had it tuned and i just recently bought an hptuners mvpi2.
In settings trans is still listed as 4l60e and prndl, they used an aem gps speedo and assuming was wired into pcm as vcm scanner shows speed.
Seems to run good so any point in changing anything or just leave it?
have abuse mode disabled and all tq management.
was going to set a different rev limiter for clutch in or "neutral" but it has no clue what gear its in and doesnt seem to care.
base-speedo160-P0300-dfco-crackle-dtc.hptcrackle-pulls.hpl

[James M]

I have an R5R30A manual in my lm7 swapped volvo.
has a p01 2002 suburban pcm that matches the engine.
Previous owner had it tuned and i just recently bought an hptuners mvpi2.
In settings trans is still listed as 4l60e and prndl, they used an aem gps speedo and assuming was wired into pcm as vcm scanner shows speed.
Seems to run good so any point in changing anything or just leave it?
have abuse mode disabled and all tq management.
was going to set a different rev limiter for clutch in or "neutral" but it has no clue what gear its in and doesnt seem to care.
base-speedo160-P0300-dfco-crackle-dtc.hptcrackle-pulls.hpl

I have the same swap (RS5R30A) paired to my 5.3. Im also running the AEM GPS speedo. It?s not linked to the PCM though and the truck stalls when I?m coasting in neutral or with the clutch in because of this. Still have my 4l60e/PRNDL settings with trans codes deleted. How is your speedometer tied into the PCM? Is it tuned for a different VSS input?