Following on from my questions about OBDC and warning lamp fault codes, I found the diagnosis section in the workshop manual (General/Base manual/Diagnosis function - 00p336.pdf page 6)
(I had seen the timing diagram before, but didn't notice the part about grounding OBDC pin 1)

Anyway, jumpering pin 1 (diagnosis terminal) to pin 4 (signal ground) and turning on the ignition brings on the fault codes display:-
Engine, Neutral, and Anti-skid lamps all flash at constant 2Hz rate - Good, no fault codes there.

But the manual page also mentions the Traction control and Cruise control lamps, and they show no activity. (TCL lamps both on, CC lamp off)
Should something be happening with those?

Some other curiosities:-
Pin 1 does go to the TCL ECU, so something might be expected from it.

Pin 1 does NOT go to the CC ECU (that I can see), so how could it respond?

Pin 1 also connects to the AirCon ECU, but it appears that no response from that ECU should be expected in this situation.

Also, the AirCon and Cruise ECUs have separate dedicated OBDC pins (11 & 13).
Maybe grounding those will do something?
Does anybody know about those?

Following on from my questions about OBDC and warning lamp fault codes, I found the diagnosis section in the workshop manual (General/Base manual/Diagnosis function - 00p336.pdf page 6)
(I had seen the timing diagram before, but didn't notice the part about grounding OBDC pin 1)

Anyway, jumpering pin 1 (diagnosis terminal) to pin 4 (signal ground) and turning on the ignition brings on the fault codes display:-
Engine, Neutral, and Anti-skid lamps all flash at constant 2Hz rate - Good, no fault codes there.

But the manual page also mentions the Traction control and Cruise control lamps, and they show no activity. (TCL lamps both on, CC lamp off)
Should something be happening with those?

Some other curiosities:-
Pin 1 does go to the TCL ECU, so something might be expected from it.

Pin 1 does NOT go to the CC ECU (that I can see), so how could it respond?

Pin 1 also connects to the AirCon ECU, but it appears that no response from that ECU should be expected in this situation.

Also, the AirCon and Cruise ECUs have separate dedicated OBDC pins (11 & 13).
Maybe grounding those will do something?
Does anybody know about those?

The only non MUT test for the Cruise Control I know of is this one,

1. Turn the ignition switch ON with the SET switch on. Then
turn the RESUME switch on within 1 second.
2. Read a diagnosis code by observing the flash display
pattern of the auto-cruise control indicator lamp in the
combination meter.

Read a diagnosis code by observing the flash display
pattern of the auto-cruise control indicator lamp in the
combination meter.

Hi, Thanks for that.

Is this procedure, and especially the diagnosis codes, documented somewhere in the factory workshop manual? (I can't find it...)

:
Hi, Thanks for that.

Is this procedure, and especially the diagnosis codes, documented somewhere in the factory workshop manual? (I can't find it...)

Section 17, had to edit had total brain fart and posted TCL :oopssign:

Section 13H in the TH,TJ, & TL, called "Traction Control System"

Sorry, not seeing it. (the diagnosis function there needs a MUT - I can't see the procedure you described)
Can't find any reference to Cruise Control (in the Traction Control section!?) or any section anywhere else for cruise control diagnosis...

had total brain fart and posted TCL

Cool, glad the brain has recovered!
Found it now, thanks.

Cool, glad the brain has recovered!
Found it now, thanks.

Yeah, the penny dropped when I could not figure how the hell you could not find it! What a PIA it was for me to find it again.:happy:
I only know of it because of when my vacuum pump quit. No codes generated though.