This paper proposes a hybrid hard/soft decode-and-forward (DF) relaying protocol with distributed turbo code (DTC), based on error detection in cooperative communications. In order to improve the performance in outage case of the channel between source and relay in uplink transmission, the relay decides whether to hard or soft decode the received signal based on the error detection before forwarding to the destination. Our simulation results show that the proposed hybrid hard/soft DF relaying outperforms conventional relaying protocols, in terms of the bit-error rate (BER) performance, in uplink cooperative communications with DTC. This is because the proposed scheme does not amplify the noise and propagate error to the destination by decoding adaptively with the help of error detection code or the use of known threshold in signal-to-noise ratio (SNR).