(Resolved) Woes - lx570 sensor lift - multiple codes, AHC not functioning (1 Viewer)

[Scott Hinckley]

I performed a front sensor lift with no issues. The next day I did the rear and things took a turn. AHC was functioning I put in LO, then N, then HI and it was clear things were not right, I no longer heard the pump. I tried to drop back to LO and N and on the dash it just blinks, no arrow.

I do not have the system error appearing on the infotainment screen or gauge screen.

I read for codes:
P1603 (eprom malfunction)
P1605 ( keep alive memory test failure)
B1443 (something with climate control)

I checked All fuses other than the 50 amp AHC fuse in the engine bay, it looks good but I was not sure how to remove and test the bus, if that’s what it’s called. I checked the AHC relay and that seemed good. I checked the 20 amp AHC fuse on the passenger side, also good.

I tried clearing the DTC codes, no change no new codes.

After sitting for an hour at the kids soccer practice it seemed to eventually drop to the N position. I had a chance to read codes again.

Now when I read for codes I get:
B1443 (non descript climate control)
C1756 (Suspension Control Relay Malfunction)
C1781 (Steering Angle Sensor Circuit)
B15EC (Backup Battery Degradation)((seems to be related to telematics communication that is sunset anyways))

It seems there is a communication issue. What’s super odd is I set to LO and the front came up, not down. But I did not hear the pump. After getting out I could see the rear did drop, but the front didn’t, I believe that’s why I thought the front raised. At the moment I have the southern squat going on. But after I put the transmission in drive the downward arrow appeared and the front dropped. Still blinking LO. After driving a few hundred feet it’s now showing as N on the dash and ride high looks correct for a sensor lift.

Other side effects include the auto leveling headlights, unfortunately they are aimed super high and I’m blasting oncoming traffic at night.

No clue what to do next. Adjusting the sensors back does nothing. I have not heard the pump at all. I’m halfway through the main AHC thread and have done quite a few searches here and Google and am not finding anything relevant. Apologies if I’ve missed something obvious.

****Resolution was replacing the AHC relay. No DTC codes returned after a clear. AHC functioning normally.

 

[TN LX570]

I would wager that your issues are just coincidence to adjusting the sensors. Moving the sensors anywhere within the factory bracket won’t cause a system malfunction.

Use techstream to run the test active tests for the suspension and steering to troubleshoot.

 

[CanadianRockyCruiser]

Have you checked the fluid level in your reservoir?

 

[doru]

A bit random errors you got. Looks like a coincidence with the AHC work.

The usual checks are:
1. battery health
2. fuses - these are complex trucks so sometimes seemingly unrelated fuses are the culprit
3. water intrusion/corrosion under dash.

All of the above are addressed in posts in this forum, just search for them.

 

[Scott Hinckley]

Degradation)

Have you checked the fluid level in your reservoir?

I have not. I have a new relay arriving today. I’m going to replace that and will look into how to check the level. Thanks

 

[Scott Hinckley]

A bit random errors you got. Looks like a coincidence with the AHC work.

The usual checks are:
1. battery health
2. fuses - these are complex trucks so sometimes seemingly unrelated fuses are the culprit
3. water intrusion/corrosion under dash.

All of the above are addressed in posts in this forum, just search for them.

Thanks for the reply. Battery is new. I’ve checked all known fuses as I’ve had experience prior with a set of random issues coming down to one fuse.

I’m going to have to read up on water intrusion…makes a a bit nervous as that came up last time I had electrical issues., and since I seem to generally have electrical issues.

I’ve had this car for 1 year and so far it’s more quirky than our high mileage 13 Land Rover.

I went over a speed bump at the gym this morning and I heard some kind of clank sound from the rear I’ve never heard before too. And I noticed the passenger rear was lower than the drivers side. Now it seems to cycle through LO,N,H, you just never know what the rear is going to do. After going from HI to N the back is now level and holding. I’ve got to check the rear sensors, wondering if one is loose and moving around.

I appreciate the reply.

 

[Scott Hinckley]

***Resolution was replacing the AHC relay. No DTC codes returned after a clear. AHC functioning normally.

 

[tbisaacs]

dang, good find!