I'm trying to fix a Ford VCMII Scan Tool with a fried transistor. The marking on the part is GCH21 and is used for Q1, Q7 and Q12 (which is fried). Note the bars above and below the G, above the H, and below the 2. The case size is a SOT23-6, SC 74 or SOT 457. The part is NOT used on a VCMI.
Doing some checks on Q1 and Q7 it appears that pins 1,2, 5 & 6 are always connected together, i.e. they are common internally, but I haven't desoldered one of the good ones to verify this.
Anyone know that this part might cross-reference to? I've spent 2-3 hours so far searching through data sheets and haven't even found a manufacturer that marks parts like this.

GCH21.JPG