| Z-town: My recently installed brand new stock NISSAN adjustable shock absorbers have no detectable change in ride quality when the Sport/Touring switch is flipped. I have confirmed that my front shock absorber actuators do rotate the respective shock absorber control rods by visual inspection (see procedure below); I did not check the rears because they are harder to reach and I suspect all 4 are in the same condition. The front two shock absorber control rods are easily rotated by hand using tweezers and (bouncing/sitting on/off the car) I notice no change in damping after trying a bunch of ~90 deg rotations (ranging from CCW around 2 turns to CW around 5 turns from the initial orientation). I suspect that all 4 shock absorbers have the same problem. The car drives fine, but the ride is stiff; stiffer than the Sport setting used to be, I think, so hopefully the Touring setting can be made available/softer. I installed the new struts myself and $pent a bunch so I could replace all the rubber bits etc along the way. I have no brake or other warning lamps lighting up. The Trouble Diagnostis procedure starting on RA-28 of the FSM doesn't describe my case (i.e. any failure modes that successfully rotate the shock absorber control rods). Comrades Jim and Paul appear to have had the same problem based on their old posts copied below. Unfortunately, I haven't found any posts that indicate how Jim and Paul fared in the longer run and I haven't been able to contact Jim or Paul directly (Jim's oceanbrite email address bounced; no reply from Paul). Anyone have contact with Jim or Paul?
Possibilities:
1. Rotating the shock absorber control rods has no effect on shock absorber damping
This appears to be the case to me (and Jim and Paul before me), but I certainly could do more testing over a larger variety of control rod orientations (how precise does control rod orientation and displacement need to be to get a change in damping?) and bouncing/sitting on/off the car is not a precise way to measure damping. I wouldn't be surprised if the new stock NISSAN adjustable shock absorbers for sale today were not identical (different design to reduce cost?) to the units on the cars in the showrooms. The replacement units could be all defective (due to manufacturing error)?
2. Initial damping is stiff in both settings, but will diverge during the initial period of use
I've driven 9000 miles (in Touring) since completing my suspension refurbishment. I still can't tell a difference between Sport and Touring.
3. User or installation error
Possible. I'm not sure how. The actuator brackets only go on the shock absorber shaft one way, so actuator to shock absorber orientation should be well controlled. The actuators are stepper motors and appear to be working so the displacement angles should be well controlled.
4. The system works while parked (during diagnostic test below), but not while vehicle is moving
I couldn't tell any difference in damping ouncing/sitting on/off the car. This is not a precise way to measure damping, though it's the method recommended in the FSM, so hopefully it would work well enough if the system was healthy.
5. ???
Anyone else have this problem before or know details of how the shock absorber control rods function?
It would help to understand what is going on inside the shock absorber when its control rod is rotated. (Should *any* 90 deg rotation cause a noticeable change in damping? How precise does initial control rod orientation need to be relative to shock absorber body? Should rotating the control rod 360 deg have no effect? Maybe I need to rotate the control rods 10 turns CW to initialize them or??? etc...)
Thanks! Diagnostic procedure to confirm that front shock absorber actuators rotate the respective shock absorber control rods: 1. Anzen daiichi ("Safety #1"!)
2. Prevent autonomous translation: Park car where it won't roll with the parking brake off, or chock a wheel etc
3. Release (lower) the parking brake
4. Switch/confirm the Sport/Touring switch to Touring
5. Ignition key to ON
6. Open and prop the hood
7. Remove (8mm) screws (2 PL) holding either front shock absorber actuator to its bracket
8. Gently jiggle and pull shock absorber actuator by hand to remove actuator from shock absorber, being careful not to yank its harness
9. Visually inspect and note the orientation of the shock absorber actuator output shaft relative to the body of the shock absorber actuator
10. Visually inspect and note the orientation of the shock absorber control rod relative to the body of the car
11. Starting with the shock absorber actuator output shaft oriented so that it mates the shock absorber control rod, gently jiggle and push the shock absorber actuator back onto the shock absorber. The holes in the body of the shock absorber actuator should line up with the holes in the mating bracket.
12. Install the 8mm screws finger tight
13. Set (raise) the parking brake (this causes the adjustable shock absorber control unit to command the shock absorber actuators to rotate to the Sport setting)
14. Remove (8mm) screws (2 PL) holding the shock absorber actuator to its bracket (same screws as Step 6 above)
15. Gently jiggle and pull shock absorber actuator by hand to remove actuator from shock absorber, being careful not to yank its harness
16. Visually inspect and note the orientation of the shock absorber actuator output shaft relative to the body of the shock absorber actuator. The orientation should be ~90 deg different than the orientation noted during Step 9
17. Visually inspect and note the orientation of the shock absorber control rod relative to the body of the car. The orientation should be ~90 deg different than the orientation noted during Step 10
18. Starting with the shock absorber actuator output shaft oriented so that it mates the shock absorber control rod, gently jiggle and push the shock absorber actuator back onto the shock absorber. The holes in the body of the shock absorber actuator should line up with the holes in the mating bracket.
19. Install the 8mm screws (Torque: 2.2-2.9 ft-lb)
20. Repeat Steps 7 through 19 for the other front shock absorber actuator, if desired
21. Close hood, remove chock, etc Referenced old posts: "
Posted by Jim Bullitt on August 06, 2001 at 3:50 PM
This message has been viewed 44 times.
Message I recently replaced front and rear struts on my 91 twin turbo and now the ability to shift from Sport to Tour has been lost. The struts (shocks) were purchase from Courtesy
Nissan and are the correct units for my car. They were installed by my local tire etc. shop and they confirmed the installation procedure with the nearest Nissan Dealer. Following the install I have the problem of running in the Sport (stiff) setting all the time. I then took the car to the nearest Nissan Dealer (50 miles away) and paid them to check the entire system, tell me what was wrong and how much it would cost to get fixed. NO LUCK, I spent $76 to find out that everything is working properly, but I still have the same problem. If anyone has any idea why I am having this problem I would sure appreciate some input.
at jbullitt@oceanbrite.com Thanks
" "
Subject Active Suspension Problem
Posted by Paul (94TTZ) on June 18, 2004 at 3:09 PM
This message has been viewed 53 times.
Message I just had all four shocks replaced with stock shocks on my TT, as well as a major brake job (mass cyl, pads, sbl's). After getting my car back the supension was stuck in Sport mode and the switch had no affect.
I took it back to the shop and they went over the car with a fine-tooth comb looking for the problem and came up empty handed. All they could tell me was: - All four actuators were tested and function fine outside the car
- The voltage to the suspension switch is 0 (ecu does not want to power the thing up) From searching here I know that the suspension won't work if the brake light is on. However, the brake light is NOT on. They suspect either the switch wiring is bad, or the ecu is bad. But seeing as it was working fine before I brought it to them, and they worked in the exact areas that affect the active suspension, my gut tells me the solution is simple. The shop is completely willing to fix the problem, if they could know what it is - any ideas guys?
Thanks in advance. From my reading I know that when you apply the parking brake it switches the suspension to the sports mode. Just a thought.
Ok, you're right. The parking brake was the problem (I was dumb and the first time I tested the parking brake was set). However, that means it was working the entire time I've been driving and I can't notice a difference between touring and sport. Do shocks need a few weeks to 'work in'?
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15:22:27 11/13/13
