The 22-year-old will miss the rest of the season after being punished for a breach of contract.
Turkish club Trabzonspor successfully claimed he had agreed to join them in 2013, before staying with Karlsruhe.
"Bayer had nothing to do with the incident," said the Turkey international.
"The club have, however, been affected by the resulting punishment in a sporting and economical sense.
"That's why, for me, it makes complete sense that I should not further harm the club and will therefore forgo my salary during the time of my exclusion."
Leverkusen, who are mid-table in the Bundesliga, face Atletico Madrid in the Champions League last 16.

He made the comments after winning the US Open doubles title with Brazil's Bruno Soares.
Judy Murray has said the new sporting and housing development would deliver "big" for tennis and the community.
More than 1,000 objections have been lodged with the authority against the development on green belt land.
Jamie Murray was asked how he felt about his success and that of brother Andy.
He said: "It is amazing what we've been able to do, being from a country with no history of tennis at all.
"It is quite amazing thinking about it and I get quite emotional talking about it.
"I think my mum especially has done some amazing things, and I hope for everything that she's done for us and for tennis in Scotland that she's able to get this tennis club built.
"We want to leave a legacy of what we're doing and it's the best way to do it. I hope the Scottish Government back her plans. I guess we'll probably find out in a few days I think.
Golfer Colin Montgomerie also supports the development, although he is no longer closely involved in the plans for the centre, which would be on land between Dunblane and Bridge of Allan.
The plan consists of a 12-court tennis venue, golfing facilities, a hotel and spa, and 19 luxury homes.
Stirling Council's planning and regulation panel rejected a planning application in December.
Planning officers said it should be refused because it was sited on greenbelt land.
They also said there was not enough affordable housing proposed and added the residential element was contrary to Scottish planning policy, because residents would have to travel for basic amenities and services.
On Wednesday Judy Murray told the hearing that she was keen to find a site suitable for a tennis centre in a "central location" of Scotland.
Ms Murray said: "For me being a Dunblane person, when this site was mentioned to me it ticked all of the boxes."
She added that it would "deliver tennis on a big scale and serve the local area too".
Ms Murray said the tennis facility would not be viable without the golf academy and housing.
"Tennis doesn't stack up by itself - it has to have other things around it," she said.
She told the public inquiry the Park of Keir development team involved her and property firm the King Group but there was no "formal" business partnership
Mark Ruskell, Scottish Green Party councillor for Dunblane and Bridge of Allan, previously spoke against the proposal.
Mr Ruskell said: "It would have been totally wrong to rip up our democratically-agreed local plan to make room for executive housing on this treasured greenbelt area.
"For over 25 years, local communities have fought against development at Park of Keir. Judy Murray had a good idea but it was in completely the wrong location. I'm sure that sporting legacy can be secured elsewhere."
The developers lodged an appeal with the Scottish government in March.
The hearing, by the Scottish government's planning and environmental appeals division, will continue to take evidence and hear from those objecting to the plan.
Bayer Leverkusen attacking midfielder Hakan Calhanoglu says he will not collect his salary during his four-month suspension.
[NEXT_CONCEPT]
Jamie Murray has urged the Scottish government to back his mother Judy's plans for a tennis centre near Dunblane.