Disculpa he modificado como me haz comentado pero me manda un error:
    
Código SQL:
Ver original- DECLARE @pFechaDel DATE = '2017-03-22' 
- DECLARE @pFechaAl DATE = '2017-03-22' 
- DECLARE @IdGuids nvarchar(MAX) =  '7078a725-ca59-4b71-bc56-21b8f456d63b' 
-   
- -- Facturas... 
- SELECT ISNULL(SUM(CH.Total),0) AS Facturas, 
- ISNULL(COUNT(CH.Total),0) AS CountFacturas, 
- (SELECT isnull(SUM(P1.Monto),0) cheques, isnull(COUNT(p1.monto),0) countcheques  FROM Finanzas.PagosrecibidosCheque P1 INNER JOIN  
- Finanzas.PagosRecibidosHeader PR ON PR.IdGuid=P1.IdGuidHeader WHERE  CONVERT(DATE, P1.Fecha , 103) BETWEEN @pFechaDel AND @pFechaAl AND   
- PR.IdGuidCliente IN (@IdGuids) AND IsNull(PR.PagoCancelado,0)=0) 
-     FROM Ventas.vCalculosHeader CH   
- WHERE CH.TipoDocto ='V3' AND CONVERT(DATE, CH.Fecha , 103) BETWEEN @pFechaDel AND @pFechaAl AND Cancelada = 0 
- AND CH.ClaveCliente IN (SELECT C.Clave FROM Clientes C WHERE C.IdGuid IN (@IdGuids)) 
Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.