No Cruise - Part II

[frafael]

guys here it's the updates:
I received my CD and check in ECU connector:
1) PIN1 - Actuator power - Comes up when brake SW is closed - OK!
2) PIN2 - Rs/Suspend - Level "1" (~11V) when SW in wheel is pushed - OK!
3) PIN3 - N/A
4) PIN4 - Set/Acce - Level "1" (~11V) when SW in wheel is pushed - OK!
5) PIN5 - Break Light - Level "1" (~11V) when break pad is pushed - OK!
6) PIN6 - N/A
7) PIN7 - Pump CTRL - "0" - Looks fine, I could not really test
8) PIN8 - ECU POWER - Comes up when I turn panel switch ON - OK!
9) PIN9 - N/A
10) PIN10 - N/A
11) PIN11 - Actuator Power ON - NOT Comes ON :c(
12) PIN12 - N/A
13) PIN13 - N/A
14) PIN14 - N/A
15) PIN15 - Speed Signal - Adequate (not real test)
16) PIN16 - Kline - Diagnostic - I don't know how to use
17) PIN17 - Valve CTRL - Leve "1" , Valve disable
18) PIN18 - Ground - oK!

So, this made me to beleive the ECU is not working.
I did open the ECU and identify the main components:
1) OKI 8 Bit CPU
2) Microchip Serial Memory
3) ELMOS ASICS, no documentation available
4) Low power 5V regulator 7805L
6) Automotive NEC SPDT relay
7) sort of smd resistors, cap, transistors and diodes.

I checked most I can (individual components), all power suplies, I reversed engineer the analog part and everythyng looks fine. The relay has I weird way to lacth when the SET SW is depress, I'd never understand why.
Looks like the PIN13 from ASIC is responsable to drain the current from the relay coil, and operate the relay but is not going to level "0". So I believe either the ASIC driver failed or the uP lost the program.
BTW, this relay is reponsable to connect PIN1 to PIN11, and power the actuator (pump em valves), I belive whenever everything works. I don't know if would happen with the car parked. With this relay opened the pump will never turn on.

Questions, where can I find a spare ECU to buy? I just found in England for $239, little expensive.

Any input?

 

[joey]

You went a lot further than I would, you can try to see if Will Tillery has one (he normally has a little bit of all most all rover parts)

www.roverguy.com

 

[frafael]

I did, but not considering myself defeated. I brought the ECU to my shop and will try more diagnostics.

--fernando

PS, tks for the link!

 

[edh]

Hi Folks

As Joey mentioned, a lot of the problems I have had(not many) turn out to have simple fixes. I have struggled with cruise control for 18 mo's on my 96 discovery. Finally found that my dash switch requires more than just a quick press when turning on. Must be gentle and sort of caress the bugger on!!

It has now turned on every time for the past month. In the past I replaced all the vacume hoses. Checked switches and spent $75.00 at local Land Rover dealer to no avail( they wanted to replace everything).

Ed

 

[joey]

edh, if that is the case, I hope you plan to change the switch....

 

[adgunn94]

i think i have the same problem with my 94. all hoses good, i did have a hole in the diaphram, but i patched it with silicone, and now it holds vaccum. will check on the brake swithc afterwhile and see if its it.

 

[adgunn94]

STILL INOP!!!!

i checked the switch, and it wasnt even mounted on the brake pedal, i put it back, still no juice to the vaccum pump. took it off, and hotwired it. no juice. im stumped.

 

[joey]

First, is the light on for the Cruise switch on the dash?

 

[adgunn94]

yeah, the light comes on,
at first i thought it was the brake switch because it was not attached to the bracket, and dangling free. i put it back in place, and nothing, i took it off, and taped it down, and nothing. no power at the vac pump.