ABS light is coming on once or twice per drive session. Stays on for a min or two then goes off on it's own. No loss of function, it's just the lamp coming on for no reason. ABS scanner shows (using K2A or K20 key): C1805 Mismatched PCM and/or ABS-TC Module Drive with scanner's real time diagnostic shows that all 4 wheel sensors are functioning properly and that the ABS pump is coming on when I lock up the brakes. Factory PCM and ABS unit, same tune I've always had that has TC disabled, no changes anything. Recently had the battery out and replace the hydroboost, but the brake system itself was completely untouched. Any ideas?