sheza65
02-18-2020, 08:08 AM
I LS swapped a 2005 Jeep Wrangler and loaded OS 12208322, then 12212156 on my 2000 Silverado 2wd 4l60e PCM 09354896 with LS Droid in conjunction with OBDLink LX TunerPro RT. The engine seems to run fine, but I can't get the factory Jeep tachometer working with or without a pull-up resistor.
The instrument cluster self-check actuation is fine and the tach worked before removing the 4.0L (32 tooth reluctor ring).
I stripped down the Jeep harness & removed most of the transmission & EFI sensor wiring. Is there something I shouldn't have removed? The grounds are good (body, sensor & motor). I don't think I removed any obvious wiring that would affect it. The Jeep PCM is just being used to run the gauges.
I followed the instructions in the screen shot to try to get the tach to work, but I used the pinouts for my 2005 Wrangler (photo of service manual). Jeep PCM C2 wires # 34 & 35 were tied together with the GM Red PCM # 10 Tach Output for the tachometer to supposedly work. In the tune, I changed Tach Low Pulses from 6 to 1 and Tach High Pulses from 6 to 1.
My problem may be the GM PCM Tach Output. The AC voltage is steady at about 6 irrespective of the RPM. This is with all three wires connected. With # 10 White disconnected from the Jeep's cam & crank wires, it doesn't want to run, but AC voltage is about 22 key on engine off & about 11 running (runs briefly like VATS is enabled & shuts down).
I tried to use a pull-up resistor (3.9K Ohm 0.5 Watt) between battery + and the GM PCM Red # 10 Tach Output. Still no tach. I even tried two resistors in series (~7.6K Ohms measured). The Jeep's crank & cam sensor wires were still connected to the Tach Output wire.
Does anyone have any insight on what might be needed to get the tach or tach output to work correctly?
The instrument cluster self-check actuation is fine and the tach worked before removing the 4.0L (32 tooth reluctor ring).
I stripped down the Jeep harness & removed most of the transmission & EFI sensor wiring. Is there something I shouldn't have removed? The grounds are good (body, sensor & motor). I don't think I removed any obvious wiring that would affect it. The Jeep PCM is just being used to run the gauges.
I followed the instructions in the screen shot to try to get the tach to work, but I used the pinouts for my 2005 Wrangler (photo of service manual). Jeep PCM C2 wires # 34 & 35 were tied together with the GM Red PCM # 10 Tach Output for the tachometer to supposedly work. In the tune, I changed Tach Low Pulses from 6 to 1 and Tach High Pulses from 6 to 1.
My problem may be the GM PCM Tach Output. The AC voltage is steady at about 6 irrespective of the RPM. This is with all three wires connected. With # 10 White disconnected from the Jeep's cam & crank wires, it doesn't want to run, but AC voltage is about 22 key on engine off & about 11 running (runs briefly like VATS is enabled & shuts down).
I tried to use a pull-up resistor (3.9K Ohm 0.5 Watt) between battery + and the GM PCM Red # 10 Tach Output. Still no tach. I even tried two resistors in series (~7.6K Ohms measured). The Jeep's crank & cam sensor wires were still connected to the Tach Output wire.
Does anyone have any insight on what might be needed to get the tach or tach output to work correctly?