C17 FI Code after decatting bike - Suzuki GSXS1000 Forum
User Tag List

LinkBack Thread Tools
post #1 of 4 Old 01-06-2020, 07:47 AM Thread Starter
Junior Member
Join Date: Apr 2019
Location: Essex, UK
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
(Thread Starter)
Question C17 FI Code after decatting bike

Hi all, Long time lurker, but first time poster

Got my bike at the start of this year and put about 2500 miles on it (I got it on 31K miles, so now approaching 34K). After summer was finished, I started collecting a few performance bits to fit over winter for next season: Power Commander, Decat, Quickshifter, Autotune.

Just before Xmas I fitted the decat, chopped off the end of the exhaust, reinstalled with the new stainless pipe, all went perfectly well. Test ride (15 miles) all went well.

Next time I went out, the FI light came on. Thought I might have not plugged the lambda back in properly or there's now an unexpected value because of the missing mid-box. Unfortunately I didn't have a bit of jumper wire on me, and whenever I killed the ignition the light would go out. I had assumed it was lambda related, so on the next garage session, I fitted the Power commander, o2 sensor remover and quickshifter. This didn't solve the issue and the light came back on. After a few times of riding, I made sure I had my jumper wire and spare key with me to leave the bike running while I did the jumper to read the code.

The code was C17 (AP sensor reading under 0.5V or over 4.85V). I didn't touch anything in/around the airbox on the side that the air pressor sensor is on, and the service manual says it's got to be one of wiring, vaccum pipe or sensor issue.


I was wondering if anyone else has had the same issue and resolved it (a google search doesn't seem to show anyone with the GSX-S1000 has had this problem before) and this thread is just as much to record how I solve it as much as it is to ask for anyone's else experience with any similar issues.

Next steps are to get the tank off, check condition of pipe from throttle body to AP sensor and check wiring. If they all check out, will be sourcing a new sensor.

Edit: This should have gone in the troubleshooting forum, I obviously didn't scroll down far enough on the main page!
mikezs is online now  
post #2 of 4 Old Yesterday, 02:32 PM Thread Starter
Junior Member
Join Date: Apr 2019
Location: Essex, UK
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
(Thread Starter)
Got time to take the bike apart today, inspected the air pressure sensor and it looked like it was in good condition, all the wiring running to it didn’t look pinched or damaged. Vacuum lines seemed in good condition and not kinked.

I removed the sensor fully from the bike after struggling to get the part number online and it was 18591-32g00. It looks like this is a £220 part from the dealers, so had a quick look on eBay to find a second hand one and got one for £15 delivered.

When I was on my way home after inspecting the sensor the light came on much more quickly which indicates to me that it’s on its way out! Will update when i have fitted the new sensor. Attached are pictures of the sensor for your enjoyment.
Attached Images
File Type: jpeg BB98C7FE-E869-452C-8341-F8A06967E6FF_1578767552295.jpeg (78.4 KB, 11 views)
File Type: jpeg 72CCE2D9-1F98-46E4-B49D-974D081A2F2C_1578767594636.jpeg (69.5 KB, 11 views)
File Type: jpeg DF386AE7-3421-465A-929A-929268DEBE9A_1578767611724.jpeg (75.0 KB, 11 views)
File Type: jpeg E4D4ED17-7C49-4C3A-A8D4-E92AD94095EF_1578767643340.jpeg (75.7 KB, 11 views)
File Type: jpeg 9EEEDB58-7CD7-45A4-9622-D858AAEE0B27_1578767696111.jpeg (322.8 KB, 11 views)

Red/Black Naked 2016 ABS
Power Commander 5, DynoJet Quickshifter, Decat, Yoshimura GP VI, Heated grips, ASV levers, R&G protection

Last edited by mikezs; Yesterday at 02:35 PM.
mikezs is online now  
post #3 of 4 Old Yesterday, 09:49 PM
Senior Member
Join Date: Apr 2016
Location: Australia.
Posts: 1,028
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 360 Post(s)
Hi Mike,
Good that you took the time to post, and hopefully solved your own problem.
Just guessing, but with the improved exhaust mod's to remove the restrictive parts, there's more air availability which now can be forced in through the air box, and the sensor internal diaphragm just fell over. Perhaps it's ear's may have popped !

Slower and Slower is offline  
post #4 of 4 Old Today, 12:26 AM
Senior Member
countryleaves's Avatar
Join Date: Nov 2016
Location: Coffs Harbour Australia
Posts: 162
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 57 Post(s)
Really valuable information Mike, thanks, I have just had black widow exhausts fitted to turn my GSXSF into a 4 into one exhaust with no decat so I've taken a note of this info

countryleaves is online now  

Quick Reply

Register Now

In order to be able to post messages on the Suzuki GSXS1000 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome