Hello all, I don't post much so don't flame me too hard. I've had my D1 through alot of tough times and am still going strong(well, at least going) with about 195k on the clock.

My wife's D2 recently has developed a slew of problems, which I now plan on tackling myself. The list includes ;radiator leak, head gasket leak, leaky rear sunroof, faulty sensor/fan mechanism for the a/c unit to realize what temperature it is in the truck thus making a digital looking 68 feel like an uncomfortable 90+ in the cabin.

Anyhow, the main thing I'm looking for help with is the fault code P1590. I've done some digging, and I have found two different possibilities, one is SLABS ECU (if anyone can define SLABS for me I'd appreciate it), and the second thing I found said faulty wheel speed sensor (much similar to the kooky ABS on my D1). I sure would appreciate some help from those who might have encountered this same code and what was done to alleviate it. Thanks in advance.. Robert S

Are you getting dash lights on? I think a wheels sensor going bad is usually the HDC, ABS and some other light that comes on and no doubt the code will tell you which wheel sensor it is. A common problem. If you have to replace the sensor, buy the sensor only, DONT buy thewhole hub which is how they used to sell it.

SLABS - Self levelling (suspension) antilock brakes (ABS) computer. It also does a few other things in the truck.

try clearing the computer - take the power away for a while and see if the code/lights return so the prob isnt just from a spike or glitch somewhere, and if it does, it no doubt is the wheel sensor triggering it - this is pretty common.

I forgot to mention that 1st off the ABS and TC lights came on, then went off after sitting for a period and being restarted. Now all 3 lights; ABS, TC, and HDC are all illuminated. Code reader read P1590 and said "Veh. Speed Idle Speed Control, Aux. Inputs, Control Aux." or something very similar to that. Cleared the codes, started truck, codes thrown again soon as the truck started. I disconnected the battery last night, and am just hoping for the best right now. RS

Disconnecting the battery might not have been the best course of action. Be prepared for more problems.

The ABS/HDC/TC lights often indicate bad hub bearings. In spite of the sealed nature, they go bad at astonishingly frequent intervals.

The error code description you provided is consistent with either a bad wheel speed sensor, or a bad hub bearing causing the speed sensor to read other than consistently.

I have a DII scheduled in for exactly this issue next month.

Well, the battery being disconnected didn't do anything more than erase the presets on the radio and erase the clock. PTSchram, would the truck being stationary throwing the code after clearing the code still indicate the hub bearings/ABS sensors? I would have thought that the truck would have had to have moved to trigger that code once it was cleared, but perhaps then it could be just a sensor that has popped out and reading (gap too far) or whatever. Things that make me go hmmmm :confused:

If the code recurs without the vehicle moving, it is unlikely to be the hub, but might be the sensor or associated wiring. The codes will clear unless the fault is persistent and present immediately upon restoring power.

I have curiously found codes indicating open circuit sensors AND airgap too large???

Pull the sensor, check for continuity between the two leads, should give you about 175 ohms resistance and an AC voltage generated when a magnet is run past the sensing surface. If this passes, start looking for continuity between the sensor connector and the ABS computer connector-if you have continuity there, you may have a computer issue.

As for losing presets and clock settings, you also lost all adaptive engine management settings-consider yourself lucky that's all that happened. People pay me well to fix the problems that arise when they disconenct their batteries.