I have been throwing DTC U1000. I have also had "RFA #2 Batt Low" (in all my research I have not found out what that means) show up on the mil. I also have a "pause" on the instrument cluster during startup. The cluster will not come up when the truck is started, but will eventually come up after the lift pump runs faster.
The pause on the instrument cluster was happening prior to installation of my lift pump, but has been more pronounced since the installation of the lift pump. It seems to be connected to battery voltage, as the lift pump will "shift gears"...it seems to be tied to the timing on the intake heater, when the intake heater shuts off, the lift pump runs noticeably faster. The batteries were tested last weekend, and both are good. They are 2 y/o Optima Red Tops. The battery voltage never drops below 13.8v while all this is going on. It goes up to 14.2 when the lift pump starts running faster.
The lift pump is installed with a single relay, lift pump power comes from the Aux post on the fuse block, and the relay energize power comes from a ignition controlled power with a power diode installed.
I have checked the DTC's with both EFI and a Tech II. I have also noticed that the U1000 does not throw when the instrument cluster is not "on", but will throw after the instrument cluster comes on line.
This was all made worse this morning when commuting to work, the instrument cluster "flashed" on and off then finally died. The needles were stuck in position....nothing worked at all. I started and shut off the engine about 3 times after arriving at work, and the cluster never came back up, the needles were still frozen in the position when the cluster failed.
Does anyone have any insight to this problem? Are the two issues (lift pump and instrument cluster) unrelated? Is the a BCM issue, wiring failure, bad cluster? Where do I start with the diag?
Thank you for the help.
The pause on the instrument cluster was happening prior to installation of my lift pump, but has been more pronounced since the installation of the lift pump. It seems to be connected to battery voltage, as the lift pump will "shift gears"...it seems to be tied to the timing on the intake heater, when the intake heater shuts off, the lift pump runs noticeably faster. The batteries were tested last weekend, and both are good. They are 2 y/o Optima Red Tops. The battery voltage never drops below 13.8v while all this is going on. It goes up to 14.2 when the lift pump starts running faster.
The lift pump is installed with a single relay, lift pump power comes from the Aux post on the fuse block, and the relay energize power comes from a ignition controlled power with a power diode installed.
I have checked the DTC's with both EFI and a Tech II. I have also noticed that the U1000 does not throw when the instrument cluster is not "on", but will throw after the instrument cluster comes on line.
This was all made worse this morning when commuting to work, the instrument cluster "flashed" on and off then finally died. The needles were stuck in position....nothing worked at all. I started and shut off the engine about 3 times after arriving at work, and the cluster never came back up, the needles were still frozen in the position when the cluster failed.
Does anyone have any insight to this problem? Are the two issues (lift pump and instrument cluster) unrelated? Is the a BCM issue, wiring failure, bad cluster? Where do I start with the diag?
Thank you for the help.
I was driving by the EGT and my ear :rofl:...and the other folks on the road.