SRC 21 code - ZR-1 Net Registry Forums

efnfast · 01-27-2018

Can't find the problem. Any thoughts?

BigJohn · 01-27-2018

You have ride control?

Disconnect the battery and see if they clear.

efnfast · 01-27-2018

Tried that. Didn't clear, but at this point it has cleared, I'll have to wait until I drive it to see if it returns.

Mystic ZR-1 · 01-27-2018

Steve
Is the car stored on the lift with wheels "hanging"?

efnfast · 01-28-2018

Quote:

Originally Posted by Mystic ZR-1

Steve
Is the car stored on the lift with wheels "hanging"?

No.
It started when I changed all four shocks two years ago. Done some trouble shooting, Pete even looked at it while it was in Chicago last winter.

Marc Haibeck · 01-28-2018

Hi Steve,
Code 21 means that the control rod is turning too slowly. Maybe there is too much friction? I often find that there is too little clearance to the actuator motor. Maybe the gear is too high above the top of the actuator mounting cup. The manual says it should be 4.5 mm. An easy way to check for binding to the actuator is to remove the clip and let the actuator rise a little. If the error goes away the problem is likely that the rod gear is sticking out too high. The bushing under the cup is supposed to set the correct height and it normally does. Sometimes I install a 1/16" fender washer under the cup to reduce the stick out. It should not be necessary, but if the stick out is too much, it will solve the problem.

efnfast · 02-04-2018

Thanks Marc (sorry, just saw this post). All four shocks were Bilstein new, that doesn't mean they were right from the factory. Checking, the stick up is correct measurement. That also doesn't mean it is correct for the situation.
Can I adjust the height of stickup by adjusting the nut on the control rod?
Oh, left front?

Marc Haibeck · 02-04-2018

You can loosen the nut to make the gear retract a little and see if it stops the error from occurring. However the nut should be torqued down so that the grommets are tight. That's when I install the washer as a shim.

Also, you could try swapping the actuators from left to right. Sometimes that produces interesting results.

efnfast · 02-04-2018

I tried swapping actuators, problem stayed with the wheel. Same question, left front?

Marc Haibeck · 02-04-2018

Yes. Error 21 is the left front turning too slow.

Also, inspect the gear for a burr or nick. Even a small one can cause upward thrust on the actuator, causing it to bind. Slide the actuator up and down on the gear. It should float freely. If not it could be binding on the gear.

01-27-2018	#1
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,492	SRC 21 code Can't find the problem. Any thoughts?

01-27-2018	#2
BigJohn Join Date: Feb 2012 Location: Ledyard,CT Posts: 8,253	Re: SRC 21 code You have ride control? Disconnect the battery and see if they clear.

01-27-2018	#3
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,492	Re: SRC 21 code Tried that. Didn't clear, but at this point it has cleared, I'll have to wait until I drive it to see if it returns.

01-27-2018	#4
Mystic ZR-1 Join Date: Jan 2010 Location: Mystic CT Posts: 2,633	Re: SRC 21 code Steve Is the car stored on the lift with wheels "hanging"?

01-28-2018	#6
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 250	Re: SRC 21 code Hi Steve, Code 21 means that the control rod is turning too slowly. Maybe there is too much friction? I often find that there is too little clearance to the actuator motor. Maybe the gear is too high above the top of the actuator mounting cup. The manual says it should be 4.5 mm. An easy way to check for binding to the actuator is to remove the clip and let the actuator rise a little. If the error goes away the problem is likely that the rod gear is sticking out too high. The bushing under the cup is supposed to set the correct height and it normally does. Sometimes I install a 1/16" fender washer under the cup to reduce the stick out. It should not be necessary, but if the stick out is too much, it will solve the problem.

02-04-2018	#7
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,492	Re: SRC 21 code Thanks Marc (sorry, just saw this post). All four shocks were Bilstein new, that doesn't mean they were right from the factory. Checking, the stick up is correct measurement. That also doesn't mean it is correct for the situation. Can I adjust the height of stickup by adjusting the nut on the control rod? Oh, left front? Last edited by efnfast; 02-04-2018 at 01:37 PM.

02-04-2018	#8
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 250	Re: SRC 21 code You can loosen the nut to make the gear retract a little and see if it stops the error from occurring. However the nut should be torqued down so that the grommets are tight. That's when I install the washer as a shim. Also, you could try swapping the actuators from left to right. Sometimes that produces interesting results.

02-04-2018	#9
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,492	Re: SRC 21 code I tried swapping actuators, problem stayed with the wheel. Same question, left front?

02-04-2018	#10
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 250	Re: SRC 21 code Yes. Error 21 is the left front turning too slow. Also, inspect the gear for a burr or nick. Even a small one can cause upward thrust on the actuator, causing it to bind. Slide the actuator up and down on the gear. It should float freely. If not it could be binding on the gear.